Crime Scene Basics
What should the first officer do at a crime scene after providing medical assistance?
Secure the scene.
Which database contains DNA profiles for the purpose of exchanging and comparing them?
CODIS
What could be physical evidence at a hit-and-run scene?
Glass fragments, paint chips, fibers and tissues.
What is a Buccal swab?
A wipe of the inner portion of the cheek to collect cells for DNA analysis.
List two ways to ensure personal safety at a crime scene.
Wear protective gear and follow established protocols to avoid contamination.
Feet coverings, mask, gloves, etc.
What are the most basic methods of crime scene recording?
Photographs, sketches, note-taking.
Which database contains fingerprints for nearly 50 million subjects?
IAFIS
Which forensic rule is used to calculate the overall frequency of occurrence of a blood type?
Product rule.
What is contamination in the context of forensic evidence?
When the evidence is mixed or tainted with other substances, affecting the lab tests.
What is a concern when packing DNA evidence?
Avoiding contamination to preserve the integrity of the sample.
What does a rough sketch NOT include?
a. location of walls, door and windows on scene
b. sketch of the suspect.
c. date, location, and time of the incident.
d. location of all recovered physical evidence.
b. sketch of the suspect.
Which database is used for firearms and bullet cartridge casing information?
NIBIN
What is the first step in the procedure for comparison of evidence?
Combinations of properties are chosen from the suspect and reference sample to be compared.
Define the term "substrate control."
A control sample used to ensure that the surface where evidence is collected does not interfere with the tests.
What role does infrared analysis play in crime scene recording?
It is not a basic method but can be used for specialized analysis.
What is the outcome of a criminal investigation almost always directly related to?
The manner in which the evidence is collected and preserved.
What does the PDQ database contain?
Chemical and color information pertaining to automotive paints.
State the difference between individual and class characteristics.
Individual characteristics can be identified as belonging to a particular person or source; class characteristics are general and can be shared among multiple sources.
What is the value of class physical evidence?
It can corroborate events with data in a nearly unbiased manner.
What are the implications of improperly handling evidence at the scene?
It can lead to challenges in prosecution and possible acquittal of suspects.
What is considered to have greater evidentiary value, physical evidence or eyewitness testimony?
Physical evidence.
Which database is used to track shoeprint images?
SICAR.
What is crucial for the successful outcome of a criminal investigation?
The manner in which the evidence is collected and preserved.
Explain the significance of resolution in forensic analysis.
It determines the amount of detail that can be visualized in the analyzed sample.
How do forensic databases contribute to solving crimes?
By providing a means to compare evidence with known samples and databases, aiding in identification and linkage of suspects to the crime scene.