CJ 1350 - Exam 1
Comparison
The process of ascertaining whether two or more objects have a common origin
T/F: Individual characteristics are properties of evidence that can be attributed to a common source with an extremely high degree of certainty.
True
T/F: Investigators should seek to disprove a theory rather than prove one
True
T/F: Petechiae is more common in strangulation cases than in hanging cases.
True
T/F: The higher the camera's f-number, the greater the depth of field of its photos.
True
T/F: The investigator should not remove trace evidence from items at the crime scene, but instead he or she should send the entire objects to the laboratory for processing.
True
T/F: The manner of collecting and preserving physical evidence at a crime scene is determined by the nature of the evidence
True
Substrate Control
Uncontaminated surface material close to an area where physical evidence has been deposited
Francis Galton
Undertook the first definitive study of fingerprints and developed a methodology of classifying them for filing.
During a comparison analysis, a suspect specimen and a control specimen are subjected to the same tests and examinations for the ultimate purpose of determining what?
Whether or not they have a common origin
expert witness
a person who is permitted to testify at a trial because of special knowledge or proficiency in a particular field that is relevant to the case.
Petechiae
a small red or purple spot caused by bleeding into the skin.
Reference Sample
anything with a known origin. it is verifiable and documented
macro lens is used for
close up photography, fingerprints
Forensic databases are NOT maintained for which of the following: dental impressions, automotive paint, fingerprints, DNA
dental impressions
Comparison
determines whether or not a suspect specimen and a standard/reference specimen have a common origin
Locard Exchange Principle
every contact leaves a trace
Evidence with class characteristics can do which of the following? Always be fitted together in the manner of a jigsaw puzzle have no evidential value link a person to a crime with a high degree of certainty exonerate an innocent suspect
exonerate an innocent suspect
Frye v. The United States (1923)
frye standard - must be generally accepted by the scientific community
What is the goal of a crime scene search?
help established what happened and identify who is responsible
image is super clear
high f-stop/ high depth of field
high depth of field
high f-stop/ image is super clear
Blunt Force Trauma
injury caused by a blow that does not penetrate the skin or other body tissues - being hit with something
What does hemoglobin transport in the blood?
oxygen
Which measurement method would be best for fast documenting the position of evidence in a sketch of an outdoor crime scene like a traffic accident?
Baseline Method
Contusion is also known as a ________________________.
Blunt Force Injury
Common characteristics of victims of hanging are:
Both Petechiae on the eyelids and blue/purplish appearance.
Standard/Reference Sample
physical evidence whose origin is known, such as blood or hair from a suspect, that can be compared to crime-scene evidence
Individual Characteristics
properties of evidence that can be attributed to a common source with an extremely high degree of certainty
Calvin Goddard
remind techniques of firearm examinations by using comparison microscope
Aperture
size of aperture opening to the lens. how much light comes in
Alphonse Bertillon
system of bodily measurements. used for the identification of an individual (anthropometry) (first system of personal identification)
Dr. Leone Lattes
technique for determining the blood group of a dried bloodstain
Falsifiabilitiy
the ability of a theory to be disproved by being tested against known information
Forensic Science
the application of science to law. enforced by police agencies
Identification
the determination of the physical or chemical identity of a substance with as near absolute certainty
Autolysis
the digestive enzyme break down carbohydrates and proteins in the cells
Asphyxia
the loss of consciousness that occurs when the body cannot get the oxygen it needs to function
Identification
the process of determining a substance's physical or chemical identity
Inductive Reasoning
the process of reaching a conclusion that is probable but not definitive based on known facts/premises
Physical evidence can be used to exonerate or exclude a person from suspicion if:
the standard reference sample (i.e., control) from the person does not share characteristics with evidence at the crime scene.
Spiral Search Pattern
usually used outside by one person. The searcher begins at a certain point and walks in increasingly larger circles to the outermost boundary of the search area.
Photo sequence of crime scene
whole, medium, close up
Hans Gross
wrote the first treatise describing the application of scientific disciplines to the field of criminal investigation
are tripods necessary for nighttime photography?
yes
Which of the following is the computerized database used to store DNA information?
CODIS
A body that displays a cherry-red discoloration might lead a pathologist to suspect what type of poisoning?
Carbon monoxide
Melendez-Diaz v. Massachusetts (2009)
Case said that the defendant has the right to question the forensic analyst if they so desire
Paint chips, random glass fragments, and synthetic fibers all exhibit what type of characteristics?
Class
CODIS
Combined DNA Index System - Comparison
When a paint chip found on a hit-and-run victim's garment is examined side-by-side with paint removed from a vehicle suspected of being involved in the incident, this is an example of what?
Comparison
T/F: Circumstantial evidence can provide a definite conclusion
False
T/F: It is not necessary to package evidence in separate containers
False
T/F: The greatest weakness of individual characteristic in physical evidence is that it cannot be related to a common origin with a high degree of certainty.
False
T/F: The higher the f-number, the wider the aperture, and the more light it allows in.
False
T/F: The known sequence of arrival of different insect groups CANNOT help to determine the postmortem interval.
False
T/F: The pathologist typically does not perform a drug analysis unless a drug overdose is suspected.
False
T/F: a warrantless search is never justified
False
Edmond Locard
Father of Crime. Locard's Exchange Principle.
The likelihood of finding class physical evidence is ________ the likelihood of finding physical evidence with individual characteristics.
Greater Than
What part of the victim's body often is covered in bags in order to prevent loss of trace evidence?
Hands
Where are defense wounds most typically seen?
Hands
What are the 5 categories of Manner of Death?
Homicide Suicide Accident Natural Undetermined
When a forensic analyst determines the chemical composition of a preparation that may contain illicit drugs such as heroin, cocaine, or barbiturates, this is an example of what?
Identification
Which lens would be best suited to photographing the details of a small but detailed tool mark found at a crime scene?
Macro Lens
Homicide, suicide, accident, natural, and undetermined are all categories of what?
Manner of Death
Do you need to be a scientist to be an expert witness?
No
The collection of standard/reference samples at the crime scene is important because they:
Permit comparisons to be made with the evidence
Investigators must test the falsifiability of all plausible theories against what?
Physical and testimonial evidence
Class Characteristics
Properties of evidence that can be associated only with a group and never with a single source
The number of pixels contained in a digital camera is directly related to the detail and sharpness of the image, which is called its what?
Resolution
Line/Strip Search Pattern
Search in straight line, with one or two investigators. great for large areas
Grid Search Pattern
Search method walking in straight lines going one way, and then going back across the side. 2 or more investigators
Which of the following should be performed first at a death scene?
Secure the scene
Wheel/Ray Search Pattern
Several investigators search in straight lines from the center to the boundary (outward) or from the boundary to the center (inward).
Responsibilities of First Responding Officer
1. Obtain medical assistance if needed 2. Call for back up 3. Detain suspects 4. excuse unauthorized personnel 5. establish boundaries of the scene / isolate area 6. keep a log of all who enters & exits scene
Lividity can be expected to be fixed after how long?
16 hours
A pathologist would expect rigor mortis to disappear after how long?
36 hours
At what angle should an evidence be photographed in a close-up to show the greatest detail?
90º
Quadrant/Zone Search Pattern
A search method in which the crime scene is divided into smaller sections (zones or quadrants) and team members are assigned to search each section. Quadrant search patterns are used to investigate vehicles
Buccal Swab
A swab of the inner portion of the cheek; cheek cells are usually collected to determine the DNA profile of an individual
Poor Depth of Field
Low F-Stop/ not everything is in focus
Which database is for fingerprints?
AFIS
Which of the following indicators can be used to estimate the time of death? Livor Mortis Eye Fluid Potassium Levels Rigor Mortis All of the Above
All of the Above
What feature of a digital camera's "night mode" allows the camera to gather as much light as possible to create the image?
Low Shutter Speed
Putrefaction and autolysis are two types of _____ processes
Decomposition
Putrefaction
Decomposition of body tissues.
If a victim's fingerprint is found on an object, the conclusion that the victim definitely touched the object at one time can be reached through which process?
Deductive Reasoning
The camera's aperture is commonly adjusted on the SLR and DSLR cameras by adjusting what?
F-Stop
SLR and DSLR are what
F-stop
If the laboratory can piece together broken glass from a window or headlight, then the evidence has ________ characteristics.
Individual
The most common methods of crime-scene recording do NOTinclude which one of the following?
Infrared Analysis
Sharp Force Trauma
Injury to soft tissue or bone caused by a sharp-edged or pointed weapon
IAFIS
Integrated Automatic Fingerprint Identification System - Comparison
Not everything is in focus
Low F-Stop / poor depth of field
To determine the sex of skeletal remains, a forensic anthropologist would examine all of the following areas of the skeleton exceptwhich?
Sternum
What are the characteristic markings on the skin caused by the discharge of a firearm called?
Stippling and tattooing
Daubert v Merril Dow Pharmaceuticals Inc (1993)
Supreme Court asserted that "general acceptance", or the Frye Standard, is not an absolute prerequisite to the admissibility of scientific evidence under the federal rules of evidence
T/F: Achieving identification requires that the number and type of tests needed to identify a substance be sufficient to exclude all other substances.
True
T/F: Aperture is the measure of the diameter of the diaphragm, which allows light into the camera.
True
T/F: Bloodstained clothing should NOT be placed in an airtight container
True
T/F: Clothing from the victim and suspect should be collected even if the presence of blood is not obvious
True
