Polygraphs
Computer Voice Stress Analyzer
Crime Scene
Evidence
Latents
100
What is a polygraph?
A mechanical device designed to ascertain whether a subject is telling the truth.
100
What does a Voice Stress Analysis detect?
It detects voice changes in people who are upset or under stress.
100
To be admissible in court, an item of evidence must be shown to be identical with that discovered at the crime scene; therefore, some method of ___________ each item of evidence must be devised.
marking
100
What is a method used in sketching which is employed outdoors by measuring the distance from two fixed objects?
Traingulation
100
Basic fingerprint patterns are arches, loops and ________.
Whorls
200
What is the polygraph's principal contribution to criminal investigations?
1) It frequently leads to a confession. 2) It may also lead to the emergence of follow-up leads (whereabouts of property, weapons, etc). 3) Also any inconsistencies in statements can be verified or challenged.
200
The changes in voice characteristics include pitch, glottal source factors, duration, and _________.
Intensity
200
Continuity of Possession is when evidence must be continuously accounted for from the time of its discovery until it is presented in court. This is also known as ______ __ ___________.
Chain of Custody
200
Methods of recording the situation, conditions, and physical evidence found at the crime scene include: notes, photographs, and _____________.
sketches
200
Controlling factors for latent fingerprints include the type of surface and finger ___________ .
pressure
300
Polygraphs records any changes in blood pressure and pulse, breathing rate, and _______?
GSR (galvanic skin response) - the electrical conductance of the skin.
300
Why are polygraphers critical of CVSA?
There is only one input - microtremors in the human voice where as polygraphs have several inputs (blood pressure and pulse, breathing rate, etc.)
300
If investigators do not comprehend the legal aspects to the preservation of physical evidence, they become ______________ to attack by defense counsel.
vulnerable
300
Sources of physcial evidence include the victim, the suspect, and the ________ _________.
crime scene
300
The means for developing latent fingerprints are powders, alternative light sources, and ___________ __________.
chemical methods.
400
Polygraph _______ is an ongoing controversy in the United States. Currently results of the polygraph tests are _________ as the sole establisher of an individual's guilt or innocence. Also polygraphs may be interpreted to mean that the subject is telling the truth, lying, or the result may be ___________?
admissibility not allowed inconclusive
400
CVSA merely tape records the questioning session; therefore, the advantages of using it include __________ and ____________.
Portability and flexibility
400
A major activity for the criminalist is comparison and interpretation of details in physical evidence to develop ___________ ______________.
Associative evidence - a speciman from the suspect be checked against the evidence from the crime scene.
400
What are 3 techniques for collecting trace evidence?
1) vacuuming 2) shaking or sweeping 3) adhesion to tape
400
How are fingerprints classified and identified?
Ridge Line Details - ridge line patterns represnt "class characteristics" and ridge line deviation details are "individual characteristics".
500
Explain how to conduct a polygraph.
Neutral questions are interspersed with critical questions, so the instrument is based on the idea that ordinarily a person is under stress when telling a lie; therefore physiological responses are produced that can be detected and measured.
500
What is a disadvantage of using the CVSA?
The Department of Defense Polygraph Institute found that the device performs no better than chance in detecting deception. In other words, guessing or flipping a coin would be as accurate.
500
What is the primary requirement for the preservation of evidence?
There be no alteration in its inherent quality or composition.
500
What 3 requiremennts need to be considered when collecting evidence?
1) Control of variables (duplicate evidence speciman) 2) Background material (unstained vs stained) 3) Sample sufficiency - need adequate size or quantity
500
Three sources needed for comparison with latent prints are police fingerprint files, a set of prints taken from a suspect, and ___________ ___________.
elimination prints - set of prints taken from each person who frequents the area.
M
e
n
u