Ch.4 Flashcards
What are the 5 types of physical evidence.
- Trace Evidence
- Impression Evidence
- Biological Evidence
- Firearm and weapons evidence
- Documents evidence
______ _____ generally can be defined as anything with tangible qualities, no matter how small, that can be measured or visualized to provide information about an actual or suspected criminal activity.
Physical Evidence
___ ____ (1902-1970), considered by many to be the father of modern criminalistics, pioneered many of the trace evidence procedures presently used in the practice of criminal investigation.
Paul Kirk
______ ________ do allow a specific piece of physical evidence to be identified as originating from a specific person, place, or thing.
Individual characteristics
Therefore, at a minimum, the following formula is recommended for use when attempting to perform identification with physical evidence:
At least __ pieces of class evidence + at least __ piece of individual evidence = ____________
2
1
Identification
The primary purpose of comparison samples is to determine the origin of an unknown piece of evidence, referred to as _____ _______, by matching it to other materials of known origin.
Questioned evidence
Comparison samples involving materials/evidence of a known origin at the crime scene include the following:
- Reference samples
- Control samples
- Elimination samples
Fingerprint Characteristics
The general class characteristics of each fingerprint type are as follows:
- Arches (least common 5%)
- Loops(most common 65%)
- Whorls(second most common 35%)
Categories of Prints
- Visible/Contaminated Prints
- Plastic Prints
- Latent Prints
Chemical developers are usually employed for developing latent prints on surfaces that are soft and porous- most commonly cloth, paper, or cardboard. Popular methods include the following:
- Iodine Fuming, works especially with paper products
- Ninhydrin. Works well on porous surfaces, including paper and finished wood.
- Silver Nitrate. Is destructive to the print so it generally is used as a last resort when other developing agents have failed
- Super Glue (cyanoacrylate)
1. rhodamine 6G
2. androx fluorescent dye spray
3. basic yellow
Chemical Developers
Listed are other surfaces, what are each of their methods:
Wet surfaces: Waxy or greasy nonporous surfaces: Bloody surfaces: Sticky surfaces: Skin surfaces:
- small particle reagent
- Sudan black
- leuco crystal violet,luminol, fluorescein, and acid fuchsin
- sticky side powder, and crystal violet
- iodine fuming,super glue fuming and amino black
_______ ____ ____ ______(EDPL) can lift dust prints from nearly any hard, flat surface as well as irregular soft surfaces such as carpet and fabric.
Electrostatic dust print lifters
Besides fingerprint evidence, recovered tools may also contain _____ __ _____ evidence of paint, wood chips, metal chips, or other material from the surface to which they were applied.
Visible or trace
Gunshot Residue (GSR)
GSR evidence is most useful if collected within __ hours after being discharged and deposited. In average conditions, GSR residue over __ hours old will no longer be of value for laboratory analyses.
3, 6
Collecting Blood Evidence
Plastic containers used for temporary transportation purposes should be replaced by paper containers or the blood evidence will usually be destroyed in ___to __ hours.
1-2
