Crj 4220 Chapter 5
latent prints
Are made when oil and perspiration naturally present on fingertips are transferred to another surface but are invisible until developed through techniques
Methods of recovering finger prints
Chemical methods can be used to recover prints from soft porous surfaces such as paper or clothing. Latent prints can be recovered through application of powders, chemicals, and glue fumes.
major types of physical evidence
Class characteristics evidence and individual evidence
5th responsibility of 1st responder
Crime scene must continuously be protected from persons at or near the scene. Authorized personnel and individuals essential to the investigation should be allowed
Touch DNA
DNA from skin cells transferred onto the surface of an object by simple contact
2nd responsibility of 1st responder
Determination has to be made about the legality of entering and searching the crime scene. A search requires a warrant or must be justified by an exception to the requirement.
individual characteristics
Features of physical evidence that allow it to be associated with a particular source.
The responsibilities of the investigator in charge
First, they should establish a crime scene debriefing team. Second, a final survey of the crime scene should be made to make sure the crime scene investigation is complete and no evidence or materials have been left behind. Lastly, the investigator in charge should ensure that all necessary reports and other documentation are completed.
corpus delicti evidence
Helps establish the elements of a crime
epithelial cells
Human tissue cells that cover internal body surfaces and can be used for DNA Analysis
Buccal swab
Involves collecting cells from the inside surfaces of the cheeks
Major Search patterns
Link method, Line method, Grid method, Zone method, Wheel/ray method, and spiral method.
4th responsibility of 1st responder
Next responsibility is to provide or summon necessary medical attention for injured parties
Visible impression prints
Occur when the print is left in a soft or sticky material, such as wet paint, clay, or putty
6th responsibility of 1st responder
Officer must establish the boundaries of the crime scene in order to protect it.
3rd responsibility of 1st responder
Officers need to be constantly mindful of potential threats to their safety, including hazardous materials, chemical threats, and dangerous people.
Gun Residue
Patterns may be found on a victim and used to estimate the distance of the muzzle from the victim.
Why is physical evidence important?
Physical Evidence can prove a crime was committed, that a suspect was at the scene, or establish the identity of persons involved. It could also exonerate the innocent and corroborate witnesses' testimony. A suspect confronted with evidence may confess. Physical evidence does not change, people's stories can/do/will change. Juries expect evidence to be presented. Sometimes, the lack of physical evidence may also provide useful information or direction.
Class characteristics
Properties of evidence that can be associated only with a group and never with a single source.
1st responsibility of 1st responder
Responding officer should be thinking about protecting the scene as well as the safety of himself or herself, other officers, and citizens.
Forensic entomology
The area of forensic science that relates to the study of insects
Forensic Anthropology
The area of forensic science that relates to the study of skeletal remains
7th responsibility of 1st responder
The initial responding officer should brief the investigators taking charge of the investigation.
2nd step in processing a crime scene
The investigator in charge must require that all personnel follow procedures to ensure safety and the integrity of the evidence being documented and collected.
3rd step in processing a crime scene
The investigator in charge should determine which items are to be collected and in what order.
Corroborative evidence
Used to support other evidence in establishing a fact in question
visible transferred prints
When ink, blood, or some other visible liquid material is transferred from the fingertip to another surface
Forensic Pathology
an area of forensic science that relates to the study of dead bodies
1st step in processing a crime scene
determine who is responsible for what and establishing the composition of the investigative team.
Primary classifications of fingerprints
loops, whorls, and arches
minutiae
small or trivial details, trifling matters
Locard's Exchange Principle
states that when a criminal comes in contact with an object or person, a cross-transfer of evidence occurs. " Expect to find evidence".
4th step in processing a crime scene
team members should ensure the proper collection, preservation, packaging, and transportation of evidence.
Forensic Odontology
the application of dentistry to legal matters
identification evidence
used to determine the identity of an individual. can be direct or circumstantial.