Bloodstain Pattern Analysis 40 hr class 1

Drag pattern

A wide type of pattern created when an existing pool of source of blood is altered by the movement of a victim or other object on a surface. Feathering of the leading edge can indicate the direction of the movement.

Artifacts

Accidental patterns made after the fact by people walking or moving through stains

Qualifications of Experts

According to the rules of evidence, a witness may qualify as an expert on the basis of knowledge, skill, training, experience or education.

Arteries close to the surface by the upper thigh

Femoral

What should BPA reports be based on?

Final opinions and written reports and courtroom testimony should be based on scientific fact with no speculation. All potential explanations should be explored and backed up using the scientific method. All BPA should be backed up with autopsy reports/lab reports, etc.

IABPA

Formation in 1983, MacDonell conducted the first advanced class for BPA, and the participants organized the International Association of Bloodstain Pattern Analysts.

Introduction of report

-Who contacted you and when -The location of the crime scene - The location of where the evidence examination occurred - A list of items received for examination - The chain of custody information in regard to the physical evidence received - Any administrative issues such as dates and times -Laboratory evidence, scene or final report

What cases tried to define an expert witness?

Ardesco Oil Co V Gibson and Lincoln & Wife v. Inhabitants of Barre- however to this day there is no clearly defined rule

What information can BPA provide an investigator?

Area of origin or convergence, type and direction of impact, mechanism by which spatter was produced, how bloodstains were deposited on evidence, position of victim, assailant or objects; movement and direction of victims, assailant or objects; support or contradiction of statements; postmortem interval information, correlation with laboratory and pathology findings.

Special Issues in a report

Areas that are not routinely addressed in every case or report- use of models, experiments, chemical enhancement, etc. Blood enhanced patterns should NOT be discussed at the same time as non-enhanced patterns. Blood enhancement should be treated as an experiment.- you also need to make sure blood enhancement is a presumptive indicator of blood and confirmatory testing is still needed.

Pressure blanching of lividity

Areas where the body may not have lividity due to being compressed from weight. The blanched or void areas may depict a pattern or shape of the surface or object that the portion of the body was in contact with.

What are the three types of Projection Mechanisms

Arterial spurt, expirated and cast- off swing

Postmortem Marbling of the Skin

Associated with bacterial gas formation and swelling of the body. It is produced by hemolysis of blood in vessels with the reaction of hemoglobin and hydrogen sulfide and the development of the greenish-black discoloration of the vessels. Decomp moves through the veins in the body making them show up really well.

Volume and pH of blood

Average adult volume is roughly 1 gal of blood (1.5 for males, 1.125 for females) and a pH of 7.4

Arteries close to the surface by axilla (by the upper arm/shoulder)

Axillary

What should you be careful with on fabrics?

Be cautious with the analysis of physical appearance and directionality of bloodstains on fabrics- they can wick in and change size and shape

What fields are used in the BPA discipline?

Biology, Physics and Mathematics

Contact wounds

Blackening effect of the gases and soot that accompany the projectile. Blackening around the edges of the wound from the soot and cherry-red discoloration of the blood from carboxyhemoglobin. Possible muzzle imprints, lacerations from gases expanding under the skin. Stellate wounds in head wounds.

Aging of blood

Blood in 24 hours goes from red to red brown to green as a result of the growth of bacteria and decomposition process.

Coffee ground emesis

Blood in the stomach lining for even a short period of time begins to be digested and looks like coffee grounds.

Blood Volume

Blood pressure must be kept above 100/40 to maintain blood supply to the brain and other tissues of the body. To maintain blood pressure and circulation the blood volume must be maintained at about 7% of the mass of the body. It has a volume of 1 L to 1 kg of mass.

Sequencing

Blood stain sequencing will show in what order blood stains were deposited by other items that have no blood under or above them

1982 publication

Bloodstain Pattern Interpretation, MacDonnell; expanded his original work

Skeletonized bloodstain

Bloodstain consisting only of an outer periphery after the central area is removed by wiping when the liquid was partially dried; can also be produced when the center of a completely dried stain flakes away.

Describe the Bloodstain Pattern Categories (flow chart) for Principles of bloodstain pattern analysis taxonomic approach (James, Kish and Sutton)

Bloodstains Passive Spatter Altered Transfer Impact Mechanism Clotted Drops Secondary Mech. Diluted Flow Projection Mech. Diffused Large Volume Insects Sequenced Voids

When taking DNA swabs what are good bloodstains to look for?

Bloodstains that are out on their own, not near your victim, or in opposing directions- they may belong to the suspect

Disadvantages of ALCV (Aqueous Leucocrystal Violet)

Boundary lines may be outlined less sharply because of the water bases. It is not suitable for use on blue-purple colored surfaces and some materials after fuming. It must be photographed after it's processed as the contrast of the impression against it's background is not permanently visible. Over time the whole thing will turn purple.

Arteries close to the surface by the arms

Brachial

Arteries close to the surface on the neck

Carotid

Notes at a crime scene should at a minimum include:

Case identifier, date and time of arrival and departure, who is present on arrival, geographic location of the scene, weather and environmental conditions.

Classifying pattern stains

Categorizing pattern stains should be based on their physical appearance which then allows us to establish the mechanisms by which a pattern was created.

Lacerations

Caused when the skin or internal organs are torn by a shearing or crushing force as a result of impact with blunt objects. They tend to be irregular with abraded contused margins and occur most commonly over bony prominences where the skin is more easily stretched and torn. There are usually tissue bridges, and they may bleed excessively. (ex: road rash, hammer)

Disadvantages of Commassie Brilliant Blue

Colors proteins present in blood and also of other body fluids, is flammable, health hazard, can only be used in laboratory settings, can damage certain surfaces, cyanoacrylate fuming may be detrimental to the process, cannot be used on blue-purple surfaces

Conclusions of your report

Compilation of the analyst's opinions based on the finding and should be listed in a sequential order, point by point. Conclusions should be clear and concise and above all they should be substantiated by the information included in the body of the report. The conclusions should represent the hypothesis that the analyst was able to prove. Because of the concise nature of the analyst's conclusions, this portion of the report will be relatively brief as compared to the introduction and the body of the report. Add "This report is based solely on the information made available to me at this time and may be changed or modified with the discovery of new information."

Herbert Leon MacDonell

Corning, New York- scientific research and practical applications of bloodstain theory (1971). Conducted experiments to re-create and duplicate bloodstain patterns found at crime scenes though law enforcement grants. Published the first modern treatise on bloodstain analysis entitled "Flight Characteristics and Stain Patterns of Human Blood".

Dr. Eduard Piotrowski

Created the earliest known significant study in bloodstain interpretation that has been documented and preserved. From Krakow, Poland. Was published in 1895. He stated "It is of the highest importance to the field of forensic medicine to give the fullest attention to bloodstains found at the scene of a crime because they can throw light on a murder and provide an explanation for the essential moments of the incident. Published "Concerning Origin, Shape, Direction and Distribution of the Bloodstains following Head Wounds Caused by Blows".

Herbert MacDonell

Credited with the evolution of bloodstain analysis in forensic science and made considerable contributions to the field in crime scene reconstruction, teaching, research and publication

What should each page of notes include?

Date, case identifier, page number and should be maintained in chronological order.

Fluorescein

Defines and enhances blood patterns- the catalytic activity of the heme then accelerates the oxidation by hydrogen peroxide of the fluorescein will then fluoresce when treated with ultraviolet light. It is a thicker solution that can be placed on a vertical surface and does not react to bleach.

1st training program for bloodstains.

1973, given by MacDonnell in Jackson, Mississippi. 2nd publication of "Laboratory Manual on the Geometric Interpretation of Human Bloodstain Evidence" was used by students.

Minimum megapixels on digital camera for bloodstains

3 megapixels

How long should blood fixing be done?

3 minutes in 30 second intervals unless it's a heavy deposit- it should be done before any cyanoacrylate

Shock from loss of blood

30% of blood volume lost

What kind of non-digital photographs should be taken of a bloodstain?

35mm, single lens reflex camera

Blood fixatives

5-sulphosalicylic acid for water based stains- methanol for methanol based stains (like Amido black)

Death from blood loss

50%

Adhesion, Cohesion and Capillarity

Descriptions of physical characteristics of liquid- Adhesion is the attractive forces between unlike molecules, Cohesion is the attractive forces between like molecules, Capillary action is a phenomena in which surface tension causes a liquid to be drawn upward into something opposing gravity.

What is the Frye standard?

Determines whether or not the procedure, evidence or proposed testimony is relevant and has gained general acceptance within the scientific community.

How is BPA accomplished?

Direct scene evaluation, careful study of photographs, detailed examination of clothing, weapons and other objects regarded as physical evidence. Hospital records, autopsy records/photographs, investigators reports and diagrams.

What should a bloodstain analyst do if information provided is scant, vague or poor quality?

Discontinue your investigation stating insufficient information exists to render a meaningful opinion on this matter

Spatter .01 mm to 3 or 4 mm

Dispersion of blood spots of varying size, created when a source of fluid blood is subjected to an external force. The minimum requirements are fluid blood source and external force great enough to overcome the physical properties of the blood.

Dr. Paul Jeserich

Documented significant work involving the study of bloodstain patterns at crime scenes (1900); a forensic chemist in Berlin who examined homicides during the first decade of the 20th century.

Writing something is blood:

Either write "visually consistent with blood" or verify it's been tested as blood - especially if you're using that pattern in an analysis

Medical conditions- bleeding from the gastrointestinal tract

Engorged hemorrhoids or colon or rectum cancer. Blood will come out black or tar colored, rarely with a red tinge.

Newtons first law of motion

A body at rest remains at rest.

Hungarian Red

A dye that stains the protein present in blood and other body fluids and has the ability to fluoresce under an ALS after being lifted with a gel lifter- allows you to see fine or barely visible details with an ALS

Bloodstain Pattern Analysis

A forensic tool that may be used to better understand what may or may not have occurred during a bloodshed event.

Discovery

A phase in the litigation process during which the opposing parties may obtain information from each other and from third parties prior to trial.

What are photomicrographs

A photograph taken through a microscope. They are very useful when describing the morphology of a bloodstain on an item of clothing.

Leuchomalachite Green test

(McPhail's Reagent) LMG oxidation is catalyzed by heme to produce a green color. The reaction is usually carried out in an acid medium with hydrogen peroxide as the oxidizer.

Splashed blood stain pattern

A quantity of blood in excess of 1 mL, subjected to a minor impact, - large central stain exhibiting minimal distortion with surrounding long, narrow spatters. There will be very little satellite spatter present. The spatter can also reverse direction because of the very acute angle and high incidence of colliding with each other.

Daubert Standard

A test of scientific acceptability applicable to the gathering of evidence in criminal cases. General acceptance of a process can be a relevant inquiry- The Daubert opinion states that the courts must assume a "gatekeeping" role regarding the admission of scientific evidence.

Scene Specific reports

This kind of report will refer to blood stains as "red brown stains" or stains visually consistent with blood" because DNA and serology has not been done yet. You can include results of presumptive tests. Reports normally concentrate on pattern analysis (size, shape, distribution, concentration, etc.) and documentation data. Scene reconstruction will be hard to do without a serology/DNA or pathology report.

Arteries close to the surface by the ankles

Tibial

Ouchterlony double diffusion test (Confirmatory blood test)

immunological technique using immunoprecipitation to detect, identify, and quantify antibodies and antigens sample of interest (with antigens) and pure antibodies place into wells and left to diffuse immune complex precipitates in gel thin white line indicates presence of antigen of interest

Area of Origin (AOO)

Two dimensional area of convergence plus the angle of impact determination for each selected stain. Creates a Spatial representation of the location of the blood source. sin -1 (W/L)

Disadvantages of Hungarian Red

Water based is not recommended for use on porous surfaces because it may be absorbed, does not react with the normal constituents of sweat in latent prints

What kind of protractor should you use for blood stain pattern analysis (area of convergence)

a zero baseline protractor that sits flush with the wall or floor

Transfer pattern

the pattern created when a wet, bloody object comes in contact with a target surface, leaving a pattern, that has the features of the object making it useful for identifying the object

voir dire examination

the preliminary examination of a juror or a witness to ascertain fitness to act as such

Medical conditions-Bleeding from the mouth and nose

cancer of the lung eroding an artery, tuberculosis, aortic aneurysm that erodes the lung, arteriovenous malformation of the lung that ruptures, ruptured varicose vein in the esophagus (from cirrhosis of the liver), nasal cancer or nasal infection eroding into the veins of the nose or sinuses, peptic ulcer.

International Association of Bloodstain Pattern Analysts

Formed in 1983 with the following objectives: Encourage and promote the science of bloodstain pattern analysis; standardize the scientific techniques of bloodstain pattern analysis; Promote education and encourage research in bloodstain pattern analysis; Inform members of the latest techniques, discoveries and developments in bloodstain pattern analysis. Has over 900 members worldwide.

Dr. Victor Balthazard

French scientist and associates conducted original research and experimentation with bloodstain trajectories and patterns (1939). Presented a paper at the 22nd Congress of Forensic Medicine entitled "Research on Blood Spatter.

Gun shot exit wounds

Frequently lacerated, often produce significant forward spatter of blood that travels in the direction of the projectile. They are not always larger as contact wounds can sometimes be larger than the exit wound.

Projected patterns

From 1mm to 1 cm and larger, usually only go about 4 ft from source, significant spines- generally caused by a breach in an artery. Can show spines, gushing and pressure fluctuations, satellite spatter.

What is the Scientific Working Group for Bloodstain Pattern Analysis?

Group organized by the FBI to establish professional forums composed of experts and scientists to address issues within specific forensic disciplines. SWIGSTAIN (The Scientific Working Group on Bloodstain Pattern Analysis) was established and the first meeting held at Quantico in 2002.

When shouldn't you use chemical enhancement of blood?

Handwritting examination, Indented impressions, Paint, fibers, GSR, DNA cross contamination,

Teichmann Test (1853) (Confirmatory blood test)

Heating dried blood in the presence of glacial acetic acid and a halide to form the hematin derivative. The crystals formed are observed microscopically.

Takayama Test (confirmatory blood test)

Heme is gently heated with pyridine under alkaline conditions in the presence of a reducing sugar such as glucose- crystals of pyridine ferriprotoporphyrin or hemochromogen are formed. Has produced positive results on ones that were negative on the Teichmann test.

What is systolic hypertension?

High blood pressure- a systolic value of greater than 160

What determines how well a blood stain pattern analysis can be completed?

How well the scene and evidence was recognized, documented and preserved at the onset of the case.

What is diastolic hypertension?

Hypertension (high blood pressure)- A pressure greater than 90

Chemiliminescence

light generated by energy released in a chemical reaction (luminol). First synthasized in 1902, discovered around 1853.

Fixed lividity

Lividity is not fixed during the first 24 hours after death- afterwards it becomes fixed. The fixation is caused by the rapture of the red blood cells as they die. It can be very difficult to discern in people who have bled to death.

Luminol

Luminesces after oxidation in acid or alkaline solution. Has been used since the early 1900's to detect blood. Works well with old and new stains. The catalytic activity of the heme group them accelerates the oxidation of the luminol, producing a blue-white to yellow-green light where blood is present. Detects 1 in 10,000,000 dilution.

Medical conditions- bleeding from the respiratory system

Lung cancer

Red blood cells (Erythrocytes)

Manufactured in the bone marrow and are the most abundant cellular component in blood. about 1 billion RBC's in only 2 or 3 drops of blood. Transport oxygen and carbon dioxide

What are some of the issues evaluated and discussed at the SWIGSTAIN?

Methods, techniques, protocols, quality assurance, education, research, legality of blood spatter, taxonomy and terminology.

False positives for presumptive blood tests

Misleading results can usually be attributed to chemical oxidants (often producing a reaction before the application of the peroxide); plant materials, or products of animal origins that may have traces of blood on them

Demonstrative Evidence

Models, diagrams, charts, computer animations and simulations- Demonstrative evidence is typically admissible to assist jurors in comprehending a witness' testimony.

Disadvantages of methanol based Amido Black

It reacts with a protein not specific for blood, is flammable and explosive, health hazard, should only be used in laboratory, not suitable for use on dark blue and black surfaces, can damage certain surfaces, fuming may be detrimental to the process, will not detect the normal constituents of latent fingerprints, fingerprint powders with metals can react strongly with methanol creating the highly explosive hydrogen gas

Flow Patterns

made by drops or large amounts of blood flowing by the pull of gravity. May change direction if the victim is moving.

What should absence of blood be considered?

It should be viewed as an issue of further inquiry, the apparent lack of bloodstains on the accused will related to types and location of the decedent's injuries or the actions taken by the accused during or after the violent act.

Non-Newtonian Fluid (Shear thinning fluids)

the shearing stress is not proportional to the shearing rate. (pie fillings thicken when stirred, quicksand gets thicker when moved) The viscosity of blood decreases with increases in velocity gradient.

Kastle-Meyer Test (Phenolphthalein)

Most commonly used in forensic laboratories, is a simple acid-base indicator- produces bright pink result. The reagent consists of reduced phenolphthalein in alkaline solution, which is oxidized by peroxide in the presence of hemoglobin in blood. Tests read after 1 minute are not considered reliable.

Diffusion

Movement of a substance from an area of higher concentration to an area of lower concentration. Surface tension is responsible for the movement of a liquid through a porous solid.

Long-range or distant contact wounds

Muzzle of the weapon is sufficiently far enough from the body so that there is no disposition of soot or stippling.

Fluorescence

Occurs when a chemical substance is exposed to a particular wave-lenth of light (usually short waves and ultraviolet and light energy is emitted at longer wavelengths.

Body of the report

Overall observations made by the analyst in regard to the bloodstain patterns. This is the foundation for all of the analyst's conclusions.

What is a more holistic approach to bloodstain terminology instead of using low, medium and high velocity?

Overlapping stain sizes and the realization that other mechanisms could produce low/medium and high spatter stains changed the thinking from labeling them from the mechanism that created them to classifying them by their physical features; size, shape, location and concentration.

What is crucial for understanding the dynamics of blood stain patterns?

Participation in laboratory experiments

What are the three taxonomic categories of blood?

Passive, Spatter and Altered

Cessation Cast-off Pattern

Pattern resulting from blood drops released from an object due to its rapid deceleration.

Passive Stains

Patterns that result from gravity such as drops and pools of blood from a wound or injury. Passive stains- contact, drops, flow, saturation and pooling, free falling volume

Altered Stains

Patterns whose appearance indicates the blood and/or pattern has undergone a physical and or physiologic alteration. Altered Stains- Clotted, dried, diluted, diffused, insects, sequenced and voids

Arteries close to the surface by the wrists

Radial

What are the physical characteristics or appearance of spatter

Size, shape and distribution

Bloodstains within crime scenes in a report

The crime scene should be presented in a systematic manner. The specific locations of bloodstain patterns within the scene should be specified in great detail. They should be depicted in a clear and concise manner. Use photographs and diagrams within the report to allow the reader to visualize what has been written.

Relative Density

The density of a substance is the measure of its weight per unit of volume and is expressed in terms of grams per cubic centimeter (has replaced the term specific gravity). Blood has a relative density of 1.060.

Arteries close to the surface under the clavicle (chest and neck area)

Subclavian

What are the four basic methods in use to determine the area of origin?

1 Stringing Method 2 Trigonometric method 3 Graphic method 4 Computer programs

Volume in a drop of blood

1 mL equals 20 drops. A single drop is 50 uL

What are factors for Daubert?

1- Whether the proposition can be tested or has been tested 2- Whether the proposition has been subjected to peer review and publication 3- Whether the methodology or technique has a known error rate 4- Whether there are standards for using the methodology 5- Whether the methodology is generally accepted

What should be requested prior to the reconstruction of a bloodstain pattern case?

1- Brief background information 2- Examination of the actual crime scene 3- Examination of the physical evidence 4- Photographs of the crime scene 5- Photographs of the physical evidence 6- Photographs of the autopsy 7- Autopsy Report 8- Serology report 9- Crime scene diagrams 10- Crime scene investigators notes or reports 11- Responding officers notes 12- EMTs notes 13- Additional forensics reports

What are two things you should look for in an autopsy or hospital record?

1- Damage to any veins or arteries 2- Whether blood was located in the nasal passages, mouth or anywhere with air passages which could have resulted in the blood being forcefully expelled from the victim

What are the IABPA's code of conduct?

1- Every member of the association shall refrain from any material misrepresentation of their standing within the IABPA 2- Every member shall refrain from any material misrepresentation of education, training, or experience in BPA 3- Every member shall refrain from material misrepresentation of data on which the expert opinion or conclusion is based

What factors should be considered when analyzing a bloodstain pattern case?

1- Never form any type of opinion until all data have been collected and synthesized. 2- If you are unable to maintain a completely objective mindset on the case, refer it to another bloodstain analyst 3- If you cannot substantiate your opinion, you do not have an opinion to render 4- How successful the analyst will be is dependent on how well they can collect, organize, and synthesize large amounts of data 5- Notes should be brief and concise statements of fact, not opinion

Lawyers needs to accomplish what four things to lay a complete foundation for scientific evidence?

1- Prove the chain of custody 2- Teach the trier of fact about the scientific area 3- Describe when and how the analysis was done 4- Interpret the evidence for the trier of fact

10 things that will enhance your effectiveness during testimony

1- Tell the truth 2- Prepare yourself by reviewing the facts 3- Remember to answer: yes, no, I don't know, I don't remember, etc. 4- If yes or no will do, one of those should be your answer 5- Limit your answer to the question then stop talking 6- Never volunteer information or answers 7- Do not assume you must have an answer for every question 8- Be cautious of repeated questions about the same point 9- Do not lose your temper 10- Speak slowly, clearly and naturally

What are the four elements of expert witness malpractice?

1- The existence of a duty owed to the plaintiff arising out of the relationship between the expert and the plaintiff 2- A negligent act or omission by the expert in breach of that duty 3- Causation 4- Damages

What factors should be considered when determining chemical enhancement of blood?

1- The suitability of the technique for the scene and the chemicals involved 2- The color of the enhancement relative to the contrast of the substrate 3- The effectiveness of the technique on porous vs non-porous substances. 4- The possible chemical damage to the surface 5- The feasibility of lifting the enhanced impression 6- The feasibility of optimizing the visibility of the impression using an alternative light source.

What are nine methods used of cross-examination to diminish an expert's credibility?

1- To attack the field of expertise- try to show something is an art, not a science 2- Exposing bias. Trying to say you only work for the prosecution or the defense and the amount of money they make from testifying 3- Attacking the chain of custody. Record keeping, evidence storage, documentation 4- Laboratory protocol. You should have a documented established procedure 5- Attacking the expert's factual basis for his or her opinion. 6- Attacking the instrument's used by the expert to do the analysis 7- Inquiry into proficiency testing or certification 8- Expert's qualifications 9- Impeachment with a learned treatise. They will ask if an expert recognizes a text or journal as a leading authority in the field.

What are the oppositions objectives in taking an expert's deposition?

1- To gather additional information 2- To attempt to impeach the expert 3- To lock the expert into a position or story that will be difficult to maintain at trial 4- To asses the expert's demeanor as a witness 5- To demonstrate to the expert's proponent the extent of knowledge and expertise the opposition posesses.

What questions should be asked of EMT when they've responded to a scene?

1- Who was assisting the injured party when you arrived 2- Did you observe any bloodstaining on the person lending assistance to the injured party? 3- With multiple injured parties, who treated who? Did the same EMT ever come in to contact with both parties? 4- How did you move or alter the position of the injured parties? 5- What types of medical interventions were used 6- Was there any blood in air passages of the victim? 7- Was the victim mobile on your arrival? 8- Did you alter the location of any piece of physical evidence?

What are ten things an expert witness can do to prepare an attorney for trial?

1-Insist on more than one witness conference 2- Establish rapport with the attorney 3- Provide the attorney with your qualifications 4- Educate the attorney- provide a glossary of terms 5-Provide the attorney with notes and reports 6- Inform the attorney if you have written any articles or treatises 7- Prepare the attorney for cross-examination of the opposing expert 8- Inform the attorney of the limitations in your expertise soo that the attorney will only use you to testify in the area you are qualified for 9- Inform the attorney of the usefulness of certain pieces of evidence. Aid the attorney in creating demonstrative evidence graphs, charts, enlargements, etc. 10- Emphasize your ethical obligations.

General points to consider when photographing bloodstain patterns:

1. Overall photographs of bloodstain evidence should occur prior to any type of alteration of the scene 2. Photograph stain patterns prior to and after using any blood enhancement techniques 3. The camera lens must be perpendicular to the plane of the bloodstain for midrange and macrophotographs. 4. Use external light sources to properly illuminate the area or items being photographed 5. Use appropriate lighting and/or lens filtration to match the color temperature of your film 6. Use scales as well as reference points within the photograph 7. When collecting bloodstained evidence at crime scenes, take photographs of the surface underneath the items being collected 8. Use a photograph log

What's the minimum you need to document regarding the appearance of bloodstains?

1. Size of overall stain pattern and individual stains 2. Overall shape of the bloodstains 3. Location of bloodstains 4. Overall distribution of the bloodstains 5. Physical appearance of the bloodstains (dry, wet, etc.) (any case related factors that may have had an effect on the formation of the bloodstain i.e. first responding officers, emergency medical personnel, temperature, air flow, poor handling of wet clothes, etc.

What are the mechanisms associated with the creation of spatter patterns

1. secondary mechanisms (blood impacts a surface or itself causing the physical properties of the blood to be overcome by the secondary impact i.e. satellite spatter) 2. Impact mechanism (Spatter pattern resulting from an object directly impacting a source of fluid blood i.e. gunshot/beating/stabbing) 3. Projection mechanism is a spatter pattern produced by the physical properties of the blood without an impact i.e. cast off, arterial, expirated).

How long should a lifter be left on a Hungarian red print

15 to 30 minutes

When was bloodstain pattern analysis admissible and proper subject for expert tesitmony?

1857 in State v Knight

What case did the Supreme Judicial Court address blood spatter interpretation and the qualifications of experts?

1875 Commonwealth v Sturtivant "close to the ken of an average layman"

Alder test (Benzidine)

1904- characteristic blue to dark blue color which may eventually turn brown. Is not normally used anymore because it is carcinogenic.

Ring Precipitin Test (confirmatory blood tests)

An immunoassay test in which a soluble antigen reacts to form a precipitate when it combines with a specific antibody in the presence of an electrolyte. A precipitate is formed if the sample is human and no reaction is seen if it isn't.

Hemoglobin

An iron-containing protein that carries oxygen from the lungs to the rest of the tissues of the body and assists in the return of carbon dioxide.

width/length = sine of angle

Angle of impact

Physical Evidence

Any and all materials or items that may be identified as being associated with a crime scene, which, by scientific evaluation, ultimately establishes the elements of the crime and provides a link among the crime scene, the victim and the assailant.

What should you document blood stains on first at a crime scene?

Any on the body

Phrases commonly used within bloodstain reports

Apparent bloodstains Stain patterns Consistent with Indicative of Would suggest Appeared to be Based on current information In the condition received At the time of examination

Advantages of Crowle's Double Stain

Can be used at crime scenes and at laboratory, simple process, suitable for use on nonporous surfaces, can be lifted with gel lifter

Advantages of Hungarian Red

Can be used at crime scenes and at the lab, simple and safe, will not detect the normal constituents of latent fingerprints, has the ability to life the enhanced blood impression with a white gelatin lifter, can fluoresce, is suitable for use on non-porous surfaces

Post mortem bleeding injuries to the skin

Can result from someone striking something as the fall (due to a heart attack, etc). and bleed as a natural function of gravity. There should be less then a cup of blood

Disadvantages of Crowle's Double Stain

Cannot be used on porous surfaces, does not fluoresce- Hungarian Red is superior stain, fuming is detrimental to process, detrimental to DNA

Spatter stains

Exhibit directionality, vary in size, and are associated with a source of blood being subjected to an external force, in addition to gravity and friction. Spatter stains- Impact mechanism, secondary mechanism, projection mechanism

Newton's Second Law of Motion

Force equals mass times acceleration (F=ma). The relationship between inertia and mass. The weight of a body is equal to the product of the mass of the body multiplied by the downward pull of gravity.

What is one primary concern of the bloodstain pattern analyst?

IF patterns have occurred as a direct result of the incident or from interventions made by EMT's, law enforcement or others trying to assist.

Camera setting for luminol

ISO- 1600, long exposure (30 secs), aperature 2.8

Hexagon OBTI (confirmatory blood test)

Immunochromatographic system, is primate specific (except ferret bloods)

Advantages of Titanium Dioxide suspension

Inexpensive, two step process, reacts with protein, turns white so is good for very dark backgrounds. Can be used after other blood-enhancement chemicals but not before- can be lifted with fingerprint tape or black gelatin lifter after being photographed

Incised Wounds

Injury produced by a sharp instrument and characterized by lack of surface abrasion and absence of bridging vessels, nerves, and smooth margins. Cutting injuries- significant cuts in blood vessels and copious bleeding. Sharply defined edges.

Crystal tests (confirmatory blood tests)

Involves the nonprotein heme group of hemoglobin, the oxygen carrying protein of erythrocytes- in dried bloodstains, the last two positions are used in the formation of crystals that are the basis for confirming the presence of blood.

Platelets (Thrombocytes) and clotting factors

Irregularly shaped cell fragments produced by megakaryocytes. They are the smallest components of human blood. Responsible for clotting and stopping blood loss. The exposure to collagen causes the platelet to change shape and grow spines and become sticky to clot. They also cause vasoconstriction at the site of the injury.

Advantages of ALCV (Aqueous Leucocrystal Violet)

It can be used at crime scenes and the lab, it's simple and inexpensive, There is minimal background discoloration on porous surfaces, It will not detect the normal constituents of latent prints Will fluoresce under ALS

Viscosity

It's resistance to changing shape or flow (thinness or thickness of a liquid)

Presumptive blood tests

Leucomalachite green, phenolphthalein

Definition of blood

Liquid connective tissue that serves two primary functions: transport and defense. It carries oxygen to the cells and carbon dioxide to the lungs for disposal through respiration. Transports food in the form of glucose, lipids and amino acids. Carries hormones and electrolytes. Removes carbon dioxide, urea, creatinine lactic acid etc. It also helps regulate temperature by distributing excessive heat throughout the body allowing it to dissipate. Stockpiles white blood cells for infection.

Are water or methanol stains preferred?

Methanol-based dyes are generally preferred over water-based dyes because they produce sharper detail in the boundary lines of the blood prints

Should chemical enhancement procedures be considered presumptive blood tests?

No because they can react with multiple things

Is a Hungarian Red print lift permanent?

No- it must be photographed within a few hours otherwise it will slowly start to spread over the whole gel lifter (and is a mirror image)

Disadvantages of Titanium Dioxide suspension

Not recommended for use on porous or light surfaces, flammable, health hazard, can only be used under laboratory conditions, can damage certain surfaces, fuming may be detrimental to process

Disadvantages of water-based Amido Black

Not recommended for use on porous surface and dark blue or black surfaces, not suitable for the detection of the normal constituents of latent fingerprints, may react with proteins from sources other than body fluids

How should doors and windows be documented in a sketch?

Note positions of doors, windows, light switches and which direction the open, close

How are bloodstain patterns documented?

Notes, sketches, diagrams, photography, and video.

What will sketches show?

Only essential items- overall view, geographic location, size and position of objects. It should complement the photographs and show a clear picture of the scene. Avoid clutter in the sketch.

Name some characteristics of a bloodstain analyst

Open minded, without prejudice, and posses a desire to learn Objective and not be swayed by the opinions or theories offered by the individual who has retained their services Never render opinions beyond what the evidence will allow no matter the amount of pressure being placed on them by their superiors, the individual who requested their assistance, or by any attorney

What kind of opinion should one avoid?

Opinions discussing the victim's cognitive state at the time of their injury (sleeping, reading, turning, frightened etc.) Opinions that overstate or amplify the significance of the bloodstain patterns. Opinions that are not based on bloodstain pattern at all (someone's size being a factor on self inflicting a wound etc.) Opinions based on a speculation of what they believe should have occurred (the gunshot wound would have produced substantial amount of backspatter, the shooter would have backspatter on them, etc.) Do not write a report that is not 100% coming from physical evidence.

o-Tolidine (Hemastix)

Ortho-tolidine is a 3,3 dimethyl derivative of benzidine. The reaction is similar to that of benzidine, is conducted under acidic conditions and produces a blue color reaction resembling that of benzidine when testing blood. Was the active ingredient ih Hemastix tests. These were also found to be carcinogenic and are no longer used.

What are the best way to document bloodstain patterns?

Photographs- it is a visually intensive forensic discipline

Physical evidence in reports

Physical evidence should be discussed in an obvious sequence (location or order it was collected). Type of examination of each item of evidence- specify where each piece of evidence was located within a scene (use photos)

What scientific fields use priniciples for bloodstain pattern analysis?

Physics, Chemistry, biology, mathematics, crime scene investigation and crime scene reconstruction.

Petechial Hemorrhaging (Tardieu spots)

Pinpoint hemorrhages produced by the rupture of small capillaries close to the skin as a result of increases in intravascular pressure. Large petechiae are referred to as ecchymoses- they may be seen within the skin, conjunctive of the eye, or mouth, and may be associated with asphyxial death such as strangulation.

What are the necessary components for clotting in blood

Platelets, fibrinogen, prothrombin, calcium and clotting factors.

PCR (poly

Pol

Arteries close to the surface by the knees

Popliteal

What is hypotensive?

Pressures below 100 systolic and /or below 50 diastolic. Also called shock.

Blood contents

Primary water, protein dissolved in plasma (7%), red cells, white cells and platelets.

Presumptive blood tests

Produce a visible color reaction or those that result in a release of light. Both types rely on the catalytic properties of blood to drive the reaction.

Tetramethylbenzidine (TMB)

Produced color change from green to blue-green. Is a testing strip not a liquid.

white blood cells (leukocytes)

Responsible for protecting the organism from pathogens. Granulocytes and non-granulocytes. Granulocytes include neutrophils, eosinophils and basophils and are produced by the bone marrow. Non granulocytes consist of lymphocytes and monocytes and are produced by the lymph nodes. WBC are also nucleated and are important for DNA.

What kind of flash is recommended for bloodstain photography?

Ring flash- regular flashes can wash out an image. You can use remote flashes or photoflood lights.

Advantages of methanol based Amido Black

Simple and inexpensive, blue black coloring is intensive, and boundary lines are sharp, Is suitable for use on porous and non-porous items

Advantages of Coomassie Brilliant Blue

Simple and inexpensive, will not detect the normal constituents of latent fingerprints, is suitable for porous and nonporous surfaces. Impressions can be lifted with a white gelatin lifter

What are the physical properties of blood

Specific gravity, viscosity and surface tension.

Federal Rule of Evidence 702

Standard for admission of expert testimony based on the application of reliable scientific methods to known facts and data- a witness qualified as an expert by knowledge, skill, experience, training or education may testify to an opinion. It needs to be helpful, relevant and reliable.

What is the Daubert standard?

Substitutes a reliability test for a relevancy test. Scientific knowledge must be derived from the scientific method supported by validation of expert testimony establishing a standard of evidentiary reliability. 1- Has the scientific theory or technique been tested? 2- Has it been subjected to peer review and publication? 3- What is the known potential error rate? What are the experts qualifications and stature in the scientific community? 4- Can the technique and it's results be explained in clarity and simplicity so the court and jury can understand it?

What causes blood droplets to stay in a sphere?

Surface tension

Two forces commonly found in fluids

Surface tension and viscosity

Arteries close to the surface on the temple

Temporal

What does BPA focus on?

The analysis of the size, shape and distribution of bloodstains resulting from bloodshed events as a means of determining the types of activities and mechanisms that produced them.

Attorneys Goals and methods of Direct Examination

The attorney will ask the expert witness short, direct and concise questions to elicit the following information: 1- Who are you (qualifications) 2- What did you do? 3- Why did you do that? 4- What did you find? (basis of your opinion) 5- What does that mean to you? (your opinion)

When doing blood stain angles what is important to rememeber?

The blood stains must be well formed and on a flat surface- do not use ones on textured ceilings or ground

Classification of Bloodstains

The conventional method was based on the correlation between the velocity of the force influencing the blood source or drop that governed the characteristics and size or diameters of the resulting bloodstains.

Final Report

The final report should consider scene analysis, laboratory analysis, information from all other forensic disciplines and variables such as law enforcement and EMS actions. You are not reporting on the case in its entirety. This is the report where we may be able to render specific reconstruction opinions regarding the bloodletting events.

What two forces can influence the movement of blood droplets

The force of gravity and the force of air resistance

Admissibility of bloodstain pattern evidence Frye vs United States

The issue of admissibility of an experts evidence is decided by the judge applying one of the two tests of admissibility. The oldest is Frye or general acceptance test of admissibility- the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.

Plasma

The liquid portion of the blood if clotting has not occurred- above the buffy coat (platelets) and red blood cells

Serum

The liquid portion of the blood if clotting has occurred- above the buffy coat (platelets) and red blood cells

Blood

The most significant and frequently encountered types of physical evidence associated with forensic investigation of death and violent crime.

What kind of opinions should be put into a report?

The opinions expressed within the bloodstain report must be substantiated scientifically. It should be concise and worded in a manner that will allow it to be understood by those completely unfamiliar with the discipline. It should be a completely objective and unbiased work product.

How does cross-examination try to undermine the expert?

The opposing attorney will try to emphasize what the expert it not, what the expert did or did not do, and what the expert does not know. The attorney will try to ask leading questions to control the witness

How should measurements be recorded?

The person reading the tape measure should record ALL the measurements.

What is crucial to the successful reconstruction of a crime scene?

The proper recognition, documentation, collection, preservation and examination of physical evidence.

The Finished Bloodstain analysis report

The purpose of the report is not to convict or to exonerate but rather to inform Bloodstain pattern analysis is only a forensic tool and should be used accordingly The report should reflect the objective and unbiased opinion of the bloodstain pattern analyst The report should be limited to only opinions that fall within the discipline of bloodstain pattern analysis Written reports must be grammatically sound The reports should be short and to the point. The excessively wordy or drawn out report will only facilitate a lengthy cross-examination

The accurate documetation of bloodstains in a crime scene assists with:

The reconstruction of the bloodshed event, maintaining a chain of custody and a peer review of the bloodstain pattern analysts opinion.

What must BPA adhere to?

The scientific method, and it must rely on principles of biology, physics and math.

Surface Tension

The spacing between molecules is fixed under controlled conditions. The electrical attractions between the molecules in this fixed spatial arrangement create cohesive forces. Surface tensions is how much force is required to break the cohesive forces of the liquid.

Inertia

The tendency of an object to resist a change in motion

Rate of Bleeding

The volume of blood loss from inside the circulation system per unit of time, whether external or internal or both- is determined by the type of vessel that is bleeding (arterial, venous or capillary), the diameter of the vessel, and the pressure of the blood in the vessel.

When should trace evidence and GSR be done?

These tests should be done before extensive bloodstain pattern examination is undertaken.

Evidence-Specific Laboratory Reports

These usually deal with the evaluation of bloodstain patterns on specific items of evidence, but they also may deal with the evaluation of scene photographs. These reports should already have the serology reports completed with presumptive testing, human testing, . These reports normally concentrate on pattern analysis (size, shape, distribution and concentration). Limited reconstruction conclusions.

What is the bloodstain pattern analysists main role?

To ascertain staining mechanisms

What is the purpose of the bloodstain pattern analysis report?

To convey the opinions of the bloodstain analyst to the attorneys, to the court, and ultimately to the jury.

Whats the purpose of bloodstain pattern documentation?

To create a clear, concise and accurate record of the bloodstain pattern's size, shape, distribution, location and overall appearance as well as all case facts that may influence the appearance and/or formation of the bloodstain pattern.

Blood Smear

Transfer blood stain that cannot be classified as a swipe or a wipe.

Intermediate range gunshot wounds

Unburned or partially burned powder particles and the projectile penetrate the skin. The powder particles produces stippling or tattooing around the entrance wound. Distances from contact up to 3 or 4 feet muzzle to target distance.

Dr Paul Kirk

University of California at Berkley (1955); prepared an affidavit regarding his findings based on bloodstain evidence to the court of common please in the case of the State of Ohio vs. Samuel Sheppard. Was a significant milestone in the recognition of bloodstain evidence by the legal system. He was able to show the relative position of an attacker and victim at the time of a beating.

Medical condition- bleeding from the skin

Venous insufficiency syndrome- ruptured varicose veins in the lower extremities- mainly seen in elderly and alcoholics. Varicosities develop when the valves in our veins become damaged and allow blood to flow backwards and pool, creating abnormally high pressure in the veins.

What stains should you choose for point of convergence?

Well defined in shape and consist of stains from all the primary zones - closer stains are more accurate

What questions must be addressed that BPA can help answer?

What events occurred, where the events occurred, when and in what sequence they occurred; who was there, who was not there and what did not occur.

Interpretation of Bloodstain Pattern analysis

What is said is equal in importance to how it is said. The way observations and opinions are phrased can dictate how well your testimony will proceed. The wording must be unbiased and accurately represent the information you intend to convey. It must be selective about how definitive or nondefinitive you are with your conclusions.

Sample introduction

What you received and when, itemize the evidence you used, "reportedly" phrased used when citing someone else's report, include injuries, serology, DNA "Within this report, stain patterns within the scene photographs that are visually consistent with "blood" will be referred to as blood and /or bloodstains. Definitions section.

Cast-Off

When blood is projected or thrown onto a surface from a blood source or object in motion like a hand or a hammer- a whiplike action and the generation of centrifugal force that overcomes the adhesive force that adheres the blood to the object. generally 4-8mm.

Parabolic flight and stringing

When doing area of origin and using a straight line you need to take into account the parabolic flight of the blood drop since it doesn't go in a straight line. Drops that are smaller and closer to the middle are more accurate. Your actual location when you get done will be at or below the area done with stringing. It represents an approximation of where the victim was.

When should you use GPS in a sketch?

When there is a significant outdoor scene that includes movement

When should you be extremely conservative with a BPA report?

When there is a small number of bloodstains. Limited number of bloodstains do not often lend themselves to useful valid analysis. Or when using photographs- particularly badly documented crime scenes.

Degrees of probability in reports

When using a phrase within a report, one must be aware that certain phrases or terms attach a degree of probability to an opinion, which the analyst may not have intended or even been aware of such as ; more likely, likely, more, tends to be. These phrases attach a degree of significance to your opinions. These phrases imply a percentage of likelihood, which may not be scientifically substantiated.

1901

When was the ABO grouping system discovered by Landstiner

Sir Alex Jeffreys

Worked on the development of DNA profiling in 1985

Trigonometric Method for area of origin

Z= tan of the angle of impact xd

Area of Convergence (AOC)

a two-dimensional view of the intersection of lines formed by drawing a line through the main axis of at least two drops of blood that indicates the general area of the source of the blood spatter

Abrasions

an area damaged by scraping or wearing away

Crossed-Over Electrophoresis (Confirmatory blood test)

antiserum and blood travel toward each other on a plate, and if a line forms (electroendosmosis), it is human blood

What should all photographs of bloodstains include?

scales

Advantages of water-based Amido Black

simple, inexpensive, will not detect the normal constituents of latent fingerprints, aluminum fingerprint powders can be used before the application of Amido Black and won't interfere

Impact angle formula

sin -1 (W/L)= impact angle

Transient Evidence

temporary; easily changed or lost; usually observed by the first officer at the scene

Angle of impact (AOI) formula

the acute angle formed between the direction of a blood drop and the plane of the surface it strikes width/length= sine of angle

terminal velocity

the constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravity

Poiseuille's Equation

volume flow rate is the quantity of blood moving through a vessel per unit of time; predicts volume flow rate in a cylindrical vessel (fluid moving in a pipe moves faster in the middle then around the edges where it's hitting the pipe)