FSC 606 Midterm - Science
American Board of Forensic Toxicology
ABFT
ANSI National Accreditation Board
ANAB
American Society of Crime Laboratory Directors/Laboratory Accreditation Board
ASCLD/LAB
rough sketch
a draft representation of all essential information and measurements at a crime scene
chain of custody
a list of all people who came into possession of an item of evidence
serology
a medical science dealing with blood serum, especially in regard to its reactions and properties
finished sketch
a precise rendering of the crime scene, usually drawn to scale
Kastle-Meyer test
a presumptive blood test using phenolphthalein and hydrogen peroxide - if blood is present, the indicator immediately turns pink
scientific method
a process that uses strict guidelines to ensure careful and systematic collection, organization, and analysis of information
satellite stain
a smaller bloodstain that originated during the formation of the parent stain as a result of blood impacting a surface
Hemastix
a strip that has been coated with tetramethylbenzidine (TMB) and will produce a green or blue-green color with the presence of hemoglobin
buccal swab
a swab of the inner portion of the cheek; cheek cells are usually collected to determine the DNA profile of an individual
confirmatory test
a test that specifically identifies one substance
projected pattern
bloodstain pattern resulting from the ejection of blood under hydraulic pressure, typically from a breach in the circulatory system
drip tail
bloodstain pattern resulting from the movement of a source of drip stains between two points
drip stain
bloodstain resulting from a falling drop that formed due to gravity
pool
bloodstain resulting from an accumulation of liquid blood on a surface
spatter stain
bloodstain resulting from an airborne drop created when external force is applied to liquid blood
transfer stain
bloodstain resulting from contact between a blood-bearing surface and another surface
insect stain
bloodstain resulting from insect activity
saturation stain
bloodstain resulting from the accumulation of liquid blood in an absorbent material
flow pattern
bloodstain resulting from the movement of a volume of blood on a surface due to gravity or movement of the target
swipe pattern
bloodstain resulting from the transfer of blood from blood-bearing surface onto another surface, with characteristics that indicate relative motion between the two surfaces
California State Division of Criminal Identification and Investigation
first state forensics laboratory
Teichmann test/Hematin test
presumptive test for blood, consists of heating dried blood in the presence of glacial acetic acid and a halide, crystals are observed microscopically (rhombic in shape)
Takayama/hemochomogen test
presumptive test for blood, reagent contains water, saturated glucose solution, 10% sodium hydroxide, and pyridine, hemochromogen crystals are observed microscopically
Phaedebas test
presumptive test for saliva detection, detects alpha amylase
acid phosphatase test
presumptive test for semen
chemiluminescence
process by which light is emitted as a product of a chemical reaction; no additional light is required for the reaction to take place
class characteristics
properties of evidence that can be associated only with a group and not with a single source
individual characteristics
properties of evidence that can be attributed to a common source with an extremely high degree of certainty
Mathieu Orfila
- "founder of forensic toxicology" -published his first paper on poisons at 26 -realized that soil can contain arsenic -One of the first people to give scientific testimony in court
Hans Gross
- Coined the term "criminalistics" -Published "Criminal Investigation" (1893) -Started the journal, "Kriminologie"
Alphonse Bertillon
-"father of anthropometry" -first forensic scientist in Europe to use fingerprints to solve a case
Dr. Paul Kirk
-"father of criminalistics" -wrote Crime Investigation chapter "Blood: Physical Investigation" - 1955 testified in Ohio v. Samuel Sheppard -recognized drying times, voids, and cast off patterns
12 Sections of AAFS
-Criminalistics -Digital and Multimedia Sciences -Engineering Science -General -Jurisprudence -Odontology -Pathology/Biology -Physical Anthropology -Psychiatry/Behavior Science -Questioned Documents -Toxicology -Forensic Nursing Sciences
Edmond Locard
-Trained in both law and medicine -Established a forensic lab in Lyon, France -Founder of the Institute of Criminalistics at University of Lyons -His success served as impetus for police labs in Berlin, Vienna, Sweden, Finland, and Holland - the "father of forensic science" -"Every contact leaves a trace"
Ouchterlony double diffusion
-carried out in an agar gel -holes are punched -antiserum is placed in center well -different stain extracts around -incubate ~24 hours -precipitate lines will form if antibody-antigen complex is present -confirmatory
Calvin Goddard
-credited with establishing the scientific exam of firearms in the US -army physician and gun enthusiast -joined the Bureau of Forensic Ballistics -named the director of the Scientific Detection Crime Laboratory at Northwestern University
Albert S. Osborn
-developed the fundamental principles of document examination -responsible for acceptance of documents as scientific evidence by the courts -wrote first scientific text in the field called "Questioned Documents" (1910)
Dr. Edward Piotrowski
-earliest known significant study of bloodstain interpretation -"Concerning Origin, Shape, Direction, and Distribution of the Bloodstains Following Head Wounds Caused by Blows"
examiner certification
-individual is certified by a particular certifying body -requires certain education and training levels -may require a test for certification -usually requires continuing education or other active involvement
Leone Lattes
-intrigued by Karl Landsteiner's blood groups -Devised a procedure for determining blood groups of dried bloodstains
Victor Balthazard
-medical examiner in Paris -helped advance fingerprints, firearms, and hair analysis -developed probability models -wrote "The Hair of Man and Animals" with Marcelle Lambert -testified using photographs and comparison techniques to identify bullets involved in a fatal shooting -studied bloodstain trajectories and patterns -recognized the trigonometric relationship between the length and width of a bloodstain
4 basic components of blood
-red blood cells -white blood cells -platelets -plasma
lab accreditation
-requires proper education and training of examiners -requires proficiency testing of examiners -requires continuing education for examiners
Sir Francis Galton
-started collecting thumbprints in 1988 -credited with developing the first classification system of fingerprints -Wrote "Finger Prints" (1892)
Walter C. McCrone
-world's preeminent microscopist -educated thousands throughout the world in the application of microscopic techniques
College of American Pathologists
CAP
National Association of Medical Examiners
NAME
National Institute of Standards and Technology
NIST
Organization of Scientific Area Committees
OSAC
LAPD
Oldest forensic laboratory in the US
President's Council of Advisors on Science and Technology
PCAST
void
absence of blood in an otherwise continuous bloodstain or bloodstain pattern
wipe pattern
altered stain resulting from an object moving through a preexisting wet bloodstain
perimeter stain
an altered stain that consists of its edge characteristics, the central area having been partially or entirely removed
expert witness
an individual whom the court determines to possess the knowledge relevant to the trial that is not expected of the average layperson
physical evidence
any and all objects that can establish that a crime has or has not been committed or can link a crime and its victim or a perpetrator
parent stain
bloodstain from which a satellite stain originated
contact/transfer pattern
bloodstain pattern created when an object with blood on it touches one that does not have blood on it
splash pattern
bloodstain pattern resulting from a large volume of liquid blood falling onto a surface
drip pattern
bloodstain pattern resulting from a liquid that dripped into another liquid, at least one of which was blood
impact pattern
bloodstain pattern resulting from an object striking liquid blood
cast-off pattern
bloodstain pattern resulting from blood drops released from an object due to its motion
back spatter pattern
bloodstain pattern resulting from blood drops which can be produced when a projectile creates an entrance wound
forward spatter pattern
bloodstain pattern resulting from blood drops which can be produced when a projectile creates an exit wound
expiration pattern
bloodstain pattern resulting from blood forced by airflow out of the nose, mouth, or a wound
directionality
characteristic of a bloodstain that indicates the direction blood was moving at the time of deposition
SALIgAE
confirmatory test for saliva, detects human salivary amylase and the substrate will turn yellow for a positive result
RSID saliva test
confirmatory test for saliva, uses monoclonal antiHSA antibodies
RSID semen test
confirmatory test for semen using seminal vesicle specific antigen
p30 test
confirmatory test for semen when used along with acid phosphatase
forensic serology
examination and analysis of body fluids
bloodstain pattern analysis
examination of the shapes, locations, and distribution of patterns of bloodstains in order to provide an interpretation of the activities that produced them
Hematrace
immunochromatographic test for human hemoglobin
Quantico
largest crime lab in the world
ALS
light that can be used to view semen stains, stains will fluoresce when viewed under the light with an orange or yellow filter, can also be used to view saliva, urine, and vaginal fluids
sequence variations
mitochondrial sequencing/SNPs
fluorescence
occurs when a chemical substance is exposed to a particular wavelength of light and light energy is emitted at longer wavelengths
standard/reference sample
physical evidence whose origin is known, such as fibers or hair from a suspect, that can be compared to crime-scene evidence
Christmas tree stain
staining test that confirms the presence of sperm, contains nuclear fast red (NFR) and picoidigocarmine (PIC)
PCR
technique used to increase the amount of a specific section of DNA in a sample using thermal cycling
presumptive test
test that presumes the presence of the questioned substance; also called a screening test.
angle of impact
the acute angle (alpha), relative to the plane of a target, at which a blood drop strikes the target
forensic science
the application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice ssytem
probative value
the degree to which a particular item of evidence is useful in, and relevant to, proving something important in a trial
comparison
the process of ascertaining whether two or more object have a common origin
identification
the process of determining a substance's physical or chemical identity
area of origin
the space in three dimensions to which the trajectories of spatter can be utilized to determine the location the spatter producing event
area of convergence
the space in two dimensions to which the directionalities of spatter stains can be retraced to determine the location of the spatter producing event
substrate control
uncontaminated surface material close to an area where physical evidence has been deposited
length polymorphisms
variation in the number of repeat units, STRs
high dose hook effect
when the excess antigen causes false negative result
Locard's exchange principle
when two objects come into contact with one another, there is exchange of materials between them