Crime Scene Investigation II

What is the most significant class characteristic in show mark examinations and why?

Tread design, because that can lead to the type and brand of shoe the print is associated with.

The interpretive value of evidence is a function of what?

Value is more context than content.

Comparison of soil sample is based on environmental variations from one sample to the next. What are some of the most significant forms of environmental variation?

Various minerals, substances, and pollens

Bevel and Gardner defined four questions that the investigator should ask about evidence. What are they?

What is it? What function did it serve? What relationship does it have to any other items of evidence of to the scene itself? What does it tell us about timing and sequencing aspects?

What is the purpose of a crime scene entry log, and when is it put in place?

When the barrier tape is put in place. To maintain order of what enters and exits the crime scene and for what reason.

When confronted with numerous individuals at a crime scene who do not appear to be directly involved, what should the officer consider before chasing them off?

directly involved, what should the officer consider before chasing them off? Directs group from primary scene, bring group under control and isolate them. Interview each of them.

What is rigor mortis?

evident stiffening of the muscles of the body

During the on-scene debriefing between the initial responding officer and the crime scene team, what information should be provided to the team?

scene team, what information should be provided to the team?All details, status, photos, fragile evidence recovered discussed.

Who is the best qualified person to examine a live victim?

technician of similar gender. In cases of sexual assault or rape, sexual assault nurse examiner (SANE) or doctor/nurse at ER.

Why must the crime scene technician retain crime scene notes even after the crime scene report is completed?

the notes should be retained after the report because the notes could have far less errors and types then the final report. The notes will also have more information than the report. The report can also relate back into the notes for future reference.

Rechecks of the scene are continued until when?

-Until it comes up negative

Describe at least three critical mistakes that occur when using video cameras in the crime scene?

-audio- early video footage, such as documenting scene on arrival, should be shot w/o audio, no subjective comments, -cameras don't see or focus as effectively as the human eye, video filled with abrupt movement is unhelpful -zoom function should be limited, precise and slow efforts in transitioning from one zoom to the next is crucial.

What is the purpose of an evidence-establishing photograph?

-capture specific items of evidence in scene in relation to obvious landmarks (doors) -allows viewer to understand where the evidence item is in relation to overall scene

What is the purpose of an overall photograph?

-depict overall condition and orientation of scene -allow every aspect of scene to be observed, they overlap

How can a crime scene technician prevent overexposure or bleaching out of close-up photographs when using fill-flash techniques?

-fill-flash techniques ensure consistent lighting across the spectrum of photographs produced at the scene -using off-set flash, oblique lighting, or a ring light

In terms of the crime scene processing goal, why is the phrase "in as pristine a condition as possible" an important distinction for the crime scene technician?

-its important because things can be moved or broken, and nothing can be in perfect condition

What are the five essential elements of crime scene sketch?

1-Heading: notation that indicates why the sketch was created. Ex. "sketch depicting primary evidence" 2-Diagram area: the drawing itself. The final drawing may be simplified (if there is a lot of unessential clutter) but the original sketch should be kept. 3-Legend: tells the viewer what the various labels used in the diagram depict. 4-Title block: provides important info relevant to the location of the scene and the creator of the sketch. Typically includes report number, address of scene, sketcher's name, time/date of creation. 5-Scale and direction notations: include 'not to scale' if it is not to scale. Orient the sketch as necessary, but indicate compass direction.

What are the two primary goals of the initial responding officer when reacting to any critical incident?

Bring the site under control and coordinate resources

Describe the differences between class and individual characteristics of evidence.

Class characteristics describes traits of evidence that allow the item to be compared to a group. Ex. size, color, manufacturing patterns. Individual characteristics allow scientists to compare item with a specific object or person. "unique"

Of the two methods used to collect tool mark evidence (collection of the entire item or casting of the mark), which is better and why?

Collection of the entire item. Poor casting might not capture important information.

If tasked to accompany a victim to the hospital, what is the officer concerned with?

Document any dying declarations or utterances made by the victim, and collect any evidence removed from the victim in the course of life saving activities.

What two additional steps are required when using polar coordinates to map a scene in which elevation data are required?

First, the difference between the datum point elevation and the sighting instrument must be determined (i.e. the height of the instrument above the datum point). The second additional step involves properly placing the sighting device in the scene, ensuring that the sighting device is at a higher elevation than any evidence items.

Why is physical evidence more objective than testimonial evidence such as eyewitness accounts?

Physical evidence never lies. Testimonial evidence has major flaws, human beings are subjective creatures.

The area contained within the initial responding officer's crime scene barrier should include three things. Identify and describe each.

Primary focal point: (easy) naturally gravitate to. Body lying on floor. Always stand out Natural entry/exit: perpetrators have to enter and exit in some fashion Secondary scenes: (problem) may include staging areas used by criminals, locations where they loaded up goods subsequent to the crime, areas where items were deposited as they fled.

How would evaluating crime scene evidence involving a pistol differ from that involving a revolver?

Revolver: casings remain in cylinder, Pistol: bullets expel

Under what conditions is the electrostatic dust lifting device used?

The ESDL can be used on almost any surface including floors walls doors and other hard surfaces as well as clothing or even paper. Can be used to recover impression from vertical/horizontal surfaces. Not effective on impressions that are wet. Also not effective on a impression with heavy deposit dirt. Used on dry surfaces only

What are the two primary venues in which analysis is accomplished?

The crime lab The application of crime scene analysis (crime scene reconstruction)

What is the primary purpose of the crime scene sketch?

The crime scene sketch serves as a graphic document to shows the layout, orientation and interrelationships of the scene and evidence. It supports the final report and it allows viewers to quickly understand the scene set-up. The sketch is not meant to replace photographs, rather to supplement the work.

When presented with a possible drug lab how does the crime scene technician respond?

The crime scene technician should leave the area and await assistance from a team properly trained and equipped to enter and make the scene safe.

In rectangular coordinates, how are fixing measurements made to surrounding walls?

The investigator fixes the evidence location by measuring, at right angles, from the evidence to the surrounding walls.

Who has the primary responsibility for estimating time of death?

The medical examiner has the primary responsibility for estimating time of death.

Describe and explain the forensic linkage triangle.

The function of the forensic evidence linkage triangle is to remind the investigator that each item discovered must be considered a mechanism for linking the scene, the victim, or the suspect in some form or fashion. Ultimately every piece of evidence is considered against this concept to determine whether any links exist and if they are of evidentiary value.

Why is it unnecessary to orient a total station to true north?

The reasoning behind this is the accuracy of the total station. Given that the instrument cannot be aligned using a magnetic compass to the same level of accuracy that the total station can measure an angle, surveying techniques suggest simply aligning to a convenient north. The internal survey created is still accurate because the total station is set in the scene by sighting on several landmarks.

How is paint layering used to differentiate two paint samples, such as when comparing a paint sample from a hit-and-run to a suspect vehicle?

The sequence layering of the various components (primers, base coats, clear coats) can offer a method of discrimination)

How does the f-stop affect the resulting photograph?

The smaller the f-stop the more light the lens lets in -The larger the f-stop the less light the lens lets in

What are the steps used to cast an impression with dental stone when the impression contains standing water?

Utilize a form and place it around the impression. If possible, build a channeling form around the impression that reaches above the waterline. Slowly direct the mixed dental stone into the pared to mix a large quantity of dental stone in order to achieve any result. In situations where the impression is filled with water the technician can sift dental stone slowly into standing water. When the water becomes viscous a form is added around the impression and the process is continued until a thorough mixture is achieved. The form will prevent additional water from seeping in and allow the mixture to set.

What is the basis of any defined actions (event segments) that the crime scene analyst identifies?

event segments are always defined by specific data

How might a natural or man-made barrier (row of trees or roadway) in the crime scene negatively affect what an officer includes in his or her initial crime scene boundary?

officer includes in his or her initial crime scene boundary? The lack any opening. Condition of bushes (ex) may make improbable that anyone moved through them

In what circumstance is baseline mapping most effective?

Baseline is best suited for exterior scenes without evident landmarks, although it can also be used inside.

What is livor mortis?

settling of blood n the body due to gravity after circulation ends

Once the body is moved and recovered from the scene, what is an area of interest that the crime scene investigator must consider? Why?

Check the area beneath the body for fingerprints, DNA, foot or footwear marks. Front and back of both hands and feet should be examined carefully of trace evidence and then photographed.

The police utilize five basic objectives in seeking their goals of preventing crime and disorder and protecting the life and liberty of their fellow citizens. What are they?

Crime repression and protection of personal liberty are both related to the criminal investigation and the processing of the crime scene, and thus they are are important objectives, The police must proactively investigate the crimes reported to them and do so in a manner that is consistent and respectful of the law and the liberties of those they encounter.

What are two variations in creating a sketch that will effectively allow the crime scene technician to document evidence on vertical objects?

Cross-projection or exploded sketch: bird's eye view with walls 'laying down' so the vertical objects can be easily seen Elevation sketch: drawing from the side view (staring directly at the wall in question). Three-dimensional sketch: usually done using software (FARO), where the viewer can virtually walk through the scene.

Describe how tape is used to collect hair and fiber evidence at the crime scene.

Cut tape 8in-10in. Apply tape to car seats, floors, upholstery. Like removing lint from shirt. Label tape of area. Place in document container

Identify the purpose of fluorescent fingerprint powder and provide an example of when it is used.

Fluorescent fingerprint powder is used when dealing with difficult surfaces that do not provide a sufficient background contrast. An example of when fluorescent fingerprint powder can be used to identify a fingerprint is when you examine currency.

In terms of a forensic analysis what is the difference between a forged writing and a traced writing?

Forged: extensive writing, or simple signatures. Tracing: lacks fluid movement. Conscious efforts to copy known writing

The fingerprinting technique is based on the surface being examined. Identify and provide an example of the our basic surface types.

Porous surface (absorb moisture): paper, cardboard, untreated wood Non Porous smooth surface (does not absorb moisture): Varnished/ painted surfaces, plastic surfaces, glass Nonporous rough surfaces: Vinyl, leather, textured countertops, other textured surfaces Special conditions: human skin, adhesive tapes, blood prints

Chisum and Rynearson identified four questions that the investigator should ask about evidence. What are they?

Predictable effects: changes to the scene or evidence that occur with some rhythm/regularity Unpredictable effects: changes that occur in an unexpected or random fashion Transitory effects: presence of ice in glass, perfumes Relational details: ability to physically place items in the scene Functional details: Does it work?

Pick any object in your immediate vicinity and, using the 8-step descriptive set, describe the item as completely as possible.

Quantity: 1, Item: Remote Control, Color: Black, with white writing, red power button, colored letter buttons, Type of construction: plastic, Approximate size: 7 inches, Identifying feature: samsung label, Condition: looks new, no scratches, Location: on the bed

Of the available methods for DNA analysis, which is the best for individualization in forensic work and why?

STR- because of how small the sample could be examined to the point of individualization. Samples as small as saliva, (licking stamp)

When is it appropriate to slow or stop EMS from entering a crime scene?

Scenes where there is putrefaction of the victim or where the head is in one corner and the body is in another.

How are bullets marked for evidence and why?

Seized in a container, should not be marked, could destroy microscopic detail.

What is the basic goal of crime scene processing?

The end goal of crime scene processing is the collection of the evidence and scene context in as a pristine condition as possible.

How might a failure to verify the address of a crime scene negatively impact the investigation?

The evidence discovered through the technically incorrect warrant may be in jeopardy

Identify and describe the five basic patterns used to search a crime scene.

- Circle or spiral search: searcher begins at a central point and spirals outward (opposite works, too) -Strip and line search: strip- lanes are established. The searcher starts at one end of the scene and begins searching each strip, reversing direction at the end of a lane and searching the next strip. Line- variation of strip search, but several searchers line up and walk side by side across the entire scene. The pace should be set by the slowest searcher and flags are left along the way of any pertinent items. The line search is the best for difficult/uneven terrain. -Grid search: Basically two strip searches on top of one another. A single searcher can double search the area by strip searching and then strip searching in a 90* opposite (Ex. up, down, up, down, then left, right, left, right) - Zone search: 2 main uses a) search small, confined spaces not easily searched with patterned movement [ex. vehicle- can divide the vehicle A-J with A-D being the passenger divisions, E-F being the trunk and engine compartment, G-J being and exterior search for prints, etc.] b) subdivide a larger scene into smaller, more manageable pieces. -Point-to-point search: Not used in the US because of it's haphazard nature. Paths are cleared from one important point to the next. Not systematic and has the tendency to become just a random walk-around.

What are the six basic processes accomplished during crime scene processing?

-Assessing -Observing -Documenting -Searching -Collecting -Processing/analyzing

What are the minimum requirements to include in a crime scene photography log?

-Basic administrative data, ID of the subject of the photo, exposure number, distance, time photo was taken, remarks/comments

In terms of intrusiveness and alteration to the scene, how might the step of documentation alter a crime scene?

-Documentation can alter a crime scene by road mapping, taking measurements for sketches, documenting bloodstain patterns, close up photography can alter a scene because you have to move items to get a closer look at the evidence.

What are the variations of the zone search and when are they used?

-First variation: used in small confined spaces, not easily searched by patterned movement, break down area into small defined areas -Second variation: subdivide larger scene into manageable pieces of ground that can be searched with other search method

Explain why it is necessary for the crime scene technician to be prepared to return to an earlier stage of the pressing model?

-It is necessary to go back because if a new piece of evidence is found then you have to go back and process that evidence, by observing, photographing, sketching and searching to bring that evidence up to speed.

What are the four key elements of crime scene documentation?

-Notes -Photograph/video -Sketches -Reports

Prior to placing a corpse in a body bag, what are some of the documentation efforts the technician must take?

-Observe, sketch, take notes, photograph evidence, collect fragile evidence

What are the three basic photograph associated with crime scene photography?

-Overall photograph -Evidence establishing photograph - Evidence close up photograph

Why is post-processing exposure to bio hazards a problem and how might it occur?

-Post-processing exposure can occur through contamination of crime scene equipment and clothing. Disposable pens and paper pads should be used at the scene and durable supplies must be cleaned thoroughly using bleach or other commercial alcohol solutions. Booties and other PPE should be employed to protect the technician, and to avoid bringing bio hazards back home or to the office.

There are three debriefings that occur during a crime scene processing: the initial debriefing by the first responding officer to the crime scene team, and two that occur after all of the primary documentation and collection activities are complete. When, where, and which whom are these debriefings conducted?

-Second Debriefing: On Scene, after checking beyond the scene right before releasing the scene, investigative team -Third Debriefing: Off sight formal, within 24 hours of the completion of scene processing, crime team, me investigator, and initial responding officer

Why is it important to establish standard team processing techniques at a mass crime scene?

-Teams working different zones of the same crime scene should work together to ensure that the work will all come together in the end to fit seamlessly. If two zones are using evidence numbers 1-10, that will cause confusion in the end. If one zone is sketching using triangulation and another team is using baseline, this will cause confusion. The same terms should be employed (cartridge, casing, bullet). Plan ahead so that the zones processing materials match.

What is the primary concern of scene assessment by the crime scene technician?

-The basic goal of scene processing is to collect as much evidence as possible in as pristine a condition as possible.

Why is sequence of order so important in crime scene processing?

-The sequence of order is so important in crime scene processing because it goes from least intrusive to most intrusive, if done any other way evidence would be lost/corrupted and there wouldn't be any proper documentation. Ruining crime scenes.

During the first recheck of the scene, are the methods used for the recheck visual or physical?

-Visual

Describe how a photograph might create an identification problem.

-When viewers can't tell where the photo was taken or what they were looking at

Describe how a photograph might create a confusion problem.

-arises from identification and orientation problems, when tech takes multiple pictures of similar items or of the scene in altered conditions without a proper photo log

What are the steps used to photograph an impression prior to casting it?

1. Ensure that the camera is squared to the impression (matching the film plane to the plane on which the impression is located) 2.Camera should be tripod mounted (closeups only) 3. Scale of reference should be inserted alongside 4. Camera is lowered to include as much detail as possible from the impression while keeping the entire impression of concern in the viewfinder 5. The technician should should take multiple photographs using the fill-flash technique 6. At least four photographs are taken at 45 angle to the impression 7. flash is moved for each photograph from the right side to the left side of the impression, to the top and to the bottom 8. place the flash at least 3ft from the impression

Name three of the five observational conditions that are inconsistent with life.

1. Massive head trauma 2. Decapitation 3. Massive blood loss 4. Evident decomposition 5. Major eviceration

Explain how the conversation of light is utilized as a search tool in the crime scene.

ALS (alternative light source) finds its widests use at the crime scene. Items that would not be seen undergo fluorescence then to be seen.

What is the difference between relative and absolute chronology?

Absolute: related to timing aspects. When did the event occur? Relative: The sequencing of event segments in relation to one another. The true backbone of reconstruction.

Describe and explain the three crime scene integrity issues that the investigator considers.

Addition of material: authorities create evidence that was not there in the beginning (footprints) this can obscure the investigators understanding of the crime which is used by the defense. Destruction of material: loss of evidentiary value. Blood on body victim while being moved into body bag will be forever destroyed. Movement of materials: result of processing. Changes relational aspects observed by investigator.

Why is the use of a single crime scene barrier ineffective?

Although functional in the early stages, a single perimeter leaves onlookers and media in too close a proximity to the scene. The barrier is visual only, and only those willing to recognize it will respect it. Multilevel containment of the scene is accomplished by using a minimum of two perimeters. The inner perimeter contains the actual crime scene. The outer perimeter creates a buffer zone and working area for the crime scene team.

What is the difference between the two general sharp force injuries, stab and incised wounds?

An incised wound is longer than it is deep and typically produce a lot of bleeding. Stab wounds are typically deeper than they are long.

What is the most appropriate response by the crime scene technician for collecting a computer for computer forensic analysis?

Appropriate shutdown procedure.

When setting up crime scene teams, what are the two basic approaches to team composition and how do they differ?

Area approach: a single team handles all activities associated with processing. The team works as one whole team. This is common in smaller departments where specialization is not an option and manpower resources are limited.- -Functional approach: the team leader designates different teams to do different activities. A photography team takes photos, a fingerprint team does the dusting/lifting, etc. When using this approach, the teams must be aware of the correct order of processing, for example, the fingerprint team cannot begin their task until the photography team has had a chance to take their pristine photos.

What type of containers are used to collect fire scene evidence in which accelerants are believed to be present?

Arson bags available from forensic suppliers

Name the three general attributes that all crime scene report narrative descriptions should have.

Detailed, with all pertinent facts and conditions documented. Accurate, with few inferences or subjective evaluations included Understandable, i.e., logical and organized

There are 5 basic objectives the officer uses to achieve these goals. Identify and briefly discuss each one.

Document the provided information: responding officer should be clear in written notes what he or she see and is being told about situation and who is giving information. Snap photographs Not become a casualty: officer safety is a big issue. Always secure and be cautious arriving at scene. Provide for emergency care: care first, evidence second. Secure/control scene: control onlookers. Establish initial perimeter and record entry and exits Release scene: debrief fully with technician or detective of what has been done and found

What is the primary observational difference between an entry an exit gunshot wound?

Entry wounds tend to be symmetrical with an abrasion ring around the outer aspect. Exit wounds tend to be asymmetric and irregular with no abrasion ring.

How can enforcing use of PPE help control scene integrity with regard to any police supervisors on scene?

If everyone in the scene is required to use proper protective clothing without exception, this alone will remind those who are nothing more than "inquiring minds" that the scene is not particularly safe. If this hint is not sufficient, then the requirement and inconvenience of putting on all of this clothing may be enough to make these individuals reconsider their need to be inside the scene. Requiring individuals to sign the scene log may also discourage their entrance because those who are on the log are more likely to be called to court and supervisors often like to come and go unnoticed.

Under what conditions and for what purpose would a fixative spray be used when casting impression evidence?

Impressions made in extremely loose soil, powders, or sand would benefit from a fixative spray. It is used to harden the soil just enough so that the impression will stay for dental stone casting.

In what situation would triangulation on a baseline be effective?

In situations involving exterior crime scenes where the field of evidence is not too widely scattered but where there are no adequate landmarks, the investigator can apply a combination of baseline and triangulation.

When evaluation glass fractures for direction of force, which fragments can be used in the evaluation?

Interior radial fracture fragments

Rifling refers to what two manufactured components of a barrel?

Interior: projections(lands), depressions(grooves)

What is the standard that the investigator uses when pursuing a solution to crime, and why is this standard necessary?

Investigate to the point of beyond a reasonable doubt. This standard is necessary because the truth will only be determined through detailed study and analysis.

What is the primary reason for using the superglue fuming technique?

It allows crime scene technicians to effectively stabilize the latent print and get them to the print examiner in a more pristine condition.

Why is it important to document investigative efforts that fail to produce evidence?

It is important to note negative results in a report to avoid a chance that a lawyer will claim improper procedure of the police or "loss of crucial evidence" to use towards his favor when in fact the negative result was just not reported.

Any good crime scene examination requires five key ingredients. What are they?

Knowledge, skills and tools, a methodical approach, flexibility, coordinated effort

With regard to evidence preservation and emergency care, what is the overriding rule for the responding officer?

Lifesaving always takes priority over evidence preservation

Identify and describe three of the four factors that affect decisions about team composition.

Single or multiple scenes: Not all crimes are confined to one scene. In a murder, there may be an assault scene and a body dump site. Area approach may be better for these cases, where separate teams process the entirety of their area. -Order of activity involving specialty examination needs: Does the primary team have the skills necessary to conduct the activity? If not, specialists must be called upon. -Available resources (equipment or personnel): if the crime scene team is small then they will be most likely to use the area approach and work as one team rather than break into smaller groups. -Physical size of the scene: if a scene is too large, size alone may prevent effective movement of the functional teams through it in a timely fashion. In that instance, zones may have to be assigned to different teams and an area approach applied.

Why is some level of inference allowable in the "Factors Pertinent to Entry and Exit" section of the crime scene report?

Some level of inference is necessary in evaluating the likelihood that a given approach was or was not used.

What are the steps used to locate fingerprint evidence in fire scene evidence?

Technique requires good lighting, and examining metal and glass surfaces at scene. If no latent prints are found, excess soot is removed by washing with tap water. Once located with soot or after removing soot, latent prints can be cleaned again with fingerprint lifters then photographed for further examination.

What is standard anatomical position and why is it important when considering the description of the gunshot wound offered by the medical examiner?

The standard anatomical position is standing, arms at the side, palms facing outward.l It is important to recognize that the ME describes wound paths based on the standard anatomical position. These descriptions relate the path to the body and nothing else. But bodies move, twist, and can be positioned in many different ways. Thus this description may have little relationship to the actual path of the bullet as it relates to the shooters and the scene.

What is the primary distinction between conditions where a gelatin lifter can be used compared with adhesive or rubber lifters?

The surfaces they can be used on. Gel lifters can be used on any surface - including porous surfaces and textured surfaces. Adhesive and rubber lifters are limited to recoveries from non porous smooth surfaces like floors

What type of information is described in the "Conditions of the Scene" section of the crime scene report?

The type of information described in "Conditions of the scene" is the cleanliness of the area and what evidence is found in the scene, while also noting rooms that were undisturbed. In this section, the description of the items of evidence can be found.

What type of information is described in the "Characteristics of the Scene" section of the crime scene report?

The type of information in the characteristic scene is pieces of the scene that would be at the scene in a day to day basis. This would include the doors, windows and furniture.

Why is the corpse reexamined at the mortuary by the crime scene investigator?

This final effort is conducted under controlled conditions at the morgue. Documentation of all wounds, recovery of any evidence, and identification data in the form of major case prints and DNA samples. Also, complete set of photographs and white light and ALS to find evidence that may not have been visible on the scene.

In what situations are rectangular coordinates on a grid particularly effective?

This method is employed in grave site excavations where evidence is measured at right angles to the grid side.

Give an example and describe fixing a regularly shaped object with triangulation.

Triangulation underlying rules are based on whether the item has a regular or irregular shape. Items that have a regular shape (they will not change with movement and contain specific identifiable points) are fixed using a minimum of four measurements. Examples of regularly shaped items include furniture, guns, or knives. In order to fix the item in the scene, the investigator takes a total of four straight-line measurements from two distinct landmarks in the room to two distinct points on the article. Each pair of measurements in effect creates a triangle.