Physical Evidence
Tangible objects, including weapons, trace evidence like hair, blood or fibers, and fingerprints. These items are real, direct evidence to the crime and the individuals involved.
Documentary Evidence
Any type of written or recorded evidence, such as a recording of a telephone conversation or a video recording of a crime. The recording is typically authenticated by an expert to show that it hasn't been doctored or manipulated in any way.
Demonstrative Evidence
Evidence that is used to help recreate or illustrate a crime.
Testimony
The evidence given by witnesses during a trial. Might come from someone who witnessed the crime or from someone who identifies as a character witness for the suspect.
Identification
The process of determining the chemical or physical characteristics of a piece of evidence with as much certainty as possible.
Comparison
The process of testing a suspect sample with a known sample to prove whether or not they share a common origin.
Probability
The frequency of an event.
Qualifications for the tests performed on evidence
Has to show that it will produce the same result multiple times for the same samples, must be sensitive in the sense that it identifies the unique characteristics of the sample, and are specific if they identify particular substances.
How forensic scientists decide which tests to use
May need a certain amount of a material in order to give the best results so these may not be used if only trace evidence of a particular substance is available.
Individual Charactristics
Evidence with characteristics that can be traced back to an individual item or person. Examples include fingerprint patterns, tread and wear patterns on shoes, blood or semen samples, firearm markings, or markings on a fired cartridge.
Ridge Characteristics/Minutiae
The ridge endings, enclosures, and other details that make up a fingerprint/
Class Characteristics
Those that can only be associated with a group and not a single source. Examples incude soil or hair
Physical Properties
Those that describe a substance or object without referring to any other substance.
Chemical Properties
Those that describe what happens when a substance reacts with another substance,
Radial Fractures
Those that extend outward from the point of impact, almost like the spokes on a wheel.
Concentric Fractures
Those fractures that form a circle around the point of impact.
Soil
Thought of as surface material from the earth, both natural and artificial. May include rocks, animal material, vegetation that lie near the surface of the ground, pieces of glass, fragments of brick or stone, and pieces of asphalt.
What narrows down possible soil matches?
Rare minerals and rocks or artificial debris.
What the casts are made of?
Silicone rubber or dental stone.
Plaster of Paris
Often used to make casts, but this substance has been widely discontinued for casting since it more easily crumbles than some of the other options.
What forensic scientists use when an impression is found in dust
Electrostatic dust print lifter.
Provides class and individual characteristics
Physical Evidence