Question

forensic science 1 - semester 1 exam review instructional sequence 3: crime scene processing

1. what is evidence?
2. define and give examples of trace evidence:
3. define locards principle of exchange:
4. give an example of how the locard principle of exchange would occur at a crime scene:
5. list the three primary ways to document the scene:
6. define the following types of evidence:

a. direct
b. circumstantial
c. class
d. individual

Explanation:

1. Evidence in forensic science is any object or information relevant to a crime. It can be used to prove or disprove facts related to a criminal investigation.
2. Trace evidence is small - scale physical evidence. Examples include hair, fibers, and glass fragments left at a crime scene.
3. Locard's Principle of Exchange states that when two objects come into contact, a transfer of materials occurs.
4. For example, if a criminal breaks a window to enter a building, glass fragments may adhere to their clothing (transfer from scene to suspect), and they may leave behind fibers from their clothing at the scene (transfer from suspect to scene).
5. The three primary ways to document a crime scene are photography, sketching, and note - taking.

6a. Direct evidence is evidence that directly proves a fact, such as an eyewitness account or a confession.
6b. Circumstantial evidence is indirect evidence that implies a fact but does not directly prove it, like fingerprints at a crime scene.
6c. Class evidence is evidence that can be associated with a group, for example, a type of tire tread pattern that many tires of a certain brand may have.
6d. Individual evidence is evidence that can be associated with a single source, such as a unique DNA profile.

Answer:

1. Any object or information relevant to a crime used to prove or disprove facts in a criminal investigation.
2. Small - scale physical evidence; examples: hair, fibers, glass fragments.
3. When two objects come into contact, a transfer of materials occurs.
4. If a criminal breaks a window, glass fragments may adhere to their clothing and they may leave fibers at the scene.
5. Photography, sketching, note - taking.

6a. Evidence that directly proves a fact, e.g., eyewitness account or confession.
6b. Indirect evidence that implies a fact but does not directly prove it, e.g., fingerprints.
6c. Evidence associated with a group, e.g., a type of tire tread pattern.
6d. Evidence associated with a single source, e.g., a unique DNA profile.