Forensic Science
Review Questions
1.
What are the four types of evidence in a criminal investigation?
The four types of evidence is physical evidence, documentary evidence, demonstrative evidence and testimony.
2.
What are individual characteristics? Give an example of an individual characteristic? Individual characteristics are properties associated with a common source to a high degree of certainty. An example of individual characteristics that forensic scientists may look for are the ridge characteristics of two fingerprint samples.
3.
What is the difference between individual characteristics and class characteristics? Class characteristics are those that can only be associated with groups not just a single source
4.
What are physical and chemical properties? Give an example of each.
Physical properties are those that describe a substance or object without referring to any other substance. For example the physical properties of glass might be its weight, size, color, and volume. The physical properties are those that an object or trace evidence has with just its physical existence, without altering it in any way with chemicals.Chemical properties are those that describe what happens when a substance reacts with another substance. For example, when the drug heroin comes into contact with the
Marquis reagent chemical it turns purple. This behavior describes the chemical property of heroin and helps forensic scientists identify its presence. 5.
What do forensic scientists do to collect and preserve soil samples?
Soil samples are typically collected from the crime scene within a 100-yard radius at various spots. Forensic scientists take great care in collecting and preserving soil samples, if soil is found on the bottom of a shoe for example the soil is left on the shoe and the entire shoe is taken to the crime lab. The
object must also be stored in such a way that any pieces of dirt that may fall off the object are retained.
Critical Thinking Questions
1.
Why do you think
1.
What are the four types of evidence in a criminal investigation?
The four types of evidence is physical evidence, documentary evidence, demonstrative evidence and testimony.
2.
What are individual characteristics? Give an example of an individual characteristic? Individual characteristics are properties associated with a common source to a high degree of certainty. An example of individual characteristics that forensic scientists may look for are the ridge characteristics of two fingerprint samples.
3.
What is the difference between individual characteristics and class characteristics? Class characteristics are those that can only be associated with groups not just a single source
4.
What are physical and chemical properties? Give an example of each.
Physical properties are those that describe a substance or object without referring to any other substance. For example the physical properties of glass might be its weight, size, color, and volume. The physical properties are those that an object or trace evidence has with just its physical existence, without altering it in any way with chemicals.Chemical properties are those that describe what happens when a substance reacts with another substance. For example, when the drug heroin comes into contact with the
Marquis reagent chemical it turns purple. This behavior describes the chemical property of heroin and helps forensic scientists identify its presence. 5.
What do forensic scientists do to collect and preserve soil samples?
Soil samples are typically collected from the crime scene within a 100-yard radius at various spots. Forensic scientists take great care in collecting and preserving soil samples, if soil is found on the bottom of a shoe for example the soil is left on the shoe and the entire shoe is taken to the crime lab. The
object must also be stored in such a way that any pieces of dirt that may fall off the object are retained.
Critical Thinking Questions
1.
Why do you think