Criminal Investigations 9th Ed - Ch 5 - Forensics / Physical Evidence Flashcards
_______ is data on which a judgment or conclusion can be based.
Evidence
______ _______ is anything real – that is, which as substance – that helps to establish the facts of a case.
Physical Evidence
_____ ______ establishes the proof of a fact without any other evidence. An example of this would be video clearly depicting the suspect committing a crime.
Direct Evidence
_______ _______ merely tends to incriminate a person. For example, a suspect’s footprint found near a crime scene. This is also known as “circumstantial evidence.”
Indirect Evidence
Evidence established by law is called ______ _____ _________ . For example, if a suspect’s blood content is 0.08 BAC then by law that suspect is intoxicated
prima facie evidence
______ ______ ______ establishes that a crime has been committed.
Corpus delicti evidence
______ ______ ______ establishes that a crime has been committed.
Corpus delicti evidence
________ ________forms a substantive part of the case or has a legitimate and effective influence on the decision of the case.
Material evidence
A ______ crime lab could provide radio equipment, equipment for disaster scenes, stakeouts, and more.
mobile
Ultraviolet light is good for finding _____ __ _______.
traces of evidence.
Common errors in collecting evidence are:
o Not collecting enough of the sample
o Not obtaining standards of comparison
o Not maintaining the integrity of the evidence
A ______ __ __________ is an object, measure, or model with which evidence is compared to determine whether both came from the same source.
standard of comparison
The _____ _____ requires law enforcement to gather all evidence that helps establish guilt or innocence.
Brady Rule
• Notes should include:
o Time
o Date
o Location the item was found
o Case number
o Description of the item
o Name of individual who found the evidence
o Name of individual who took it into custody
______ __________ are transferred to a surface by dirt/soil on the ridges of the fingers or residue oil.
Latent Fingerprints
_______ may be developed using fingerprint powder, magana brush techniques, laser technology, gelatin lifters, and cyanoacrylate.
fingerprints
AFIS stands for:
“automated fingerprint identification system”
• A “______ ________” positively identifies a person. Except for identical twins, no two individuals have the same DNA structure.
generic fingerprint
_ _ _ profiling uses material from which chromosomes are made to identify individuals positively.
DNA
DNA was discovered in
1868
______ has the lowest clearance rate of any index crime.
Burglary
Burglary can be a “______” crime that leads to more serious violent crimes in the future.
getaway
• There are TWO types of DNA used in forensic analyses:
o Nuclear DNA (nDNA) which is more discriminating and is typically analyzed in evidence containing blood, semen, saliva, body tissues, and hairs that have tissue at their root ends.
o Mitochondrial DNA (mtDNA) is typically analyzed in evidence containing naturally shed hairs, hair fragments, bones, and teeth.
o Examples: If a crime scene technician collected a sample of suspected semen stains from the bed sheet inside a rape/murder scene; ________ DNA (_DNA) analyses would probably be used.
Nuclear (nDNA)
o Examples: If a crime scene technician collected a sample from a small bone found in a shallow grave in the woods, _________ DNA (__DNA) analyses would probably be used.
Mitochondrial (mtDNA)
NDIS
National DNA Index System
CODIS
Combined DNA Index System
Blood evidence can be identified as _____ or _____. It can not determine age or race.
animal or human
When collecting hair evidence, attempt to obtain ____ - _____ full hairs from appropriate parts of the suspect’s body.
20-50
• A hair shaft consist of:
o Cuticle: the outside consisting of overlapping scales that always point toward the tip
o Cortex: consisting of elongated cells
o Medulla: the center of the hair
Ballistics is the study of the dynamics of projectiles, from propulsion through flight to impact.
A shorter definition is “the study of the functioning of firearms.”
The ____ is the inside portion of the weapon’s barrel
bore
The raised ridges surrounding the bore are called _____ and recessed areas called ______.
lands
grooves
The lands & grooves make up the
rifling
________ ________ can determine the elements of pieces of glass.
Spectrographic analysis
_____ evidence can determine the sequence of bullets fired through a piece of glass.
Glass
_______ ______ are ridges which are rib-shaped marks with a wavelike pattern and are almost always concave in the direction from which the crack was propagating.
Wallner Lines
• The __ Rule: “Ridges on radial cracks are at right angles to the rear”
4R
When collecting soil evidence, collect _____ ______ of ______ soil into a container.
one pound of Comparison
• Forensic Information System for Handwriting (FISH) is
maintained by the Secret Service and analyses documents.
To simplify testimony in court, it is practical to have one officer collect the item of evidence and another _____ ____ .
Take notes
