Forensics unit 1 test

The Locard Principal

The Locard Principal

When two objects come into contact with each other, traces of each are exchanged. It's important because it allows scientists to see what objects have been in contact with a crime scene or evidence.

Chain of custody

Keeping an absolutely complete record of every person who has had access to the evidence. It is essential to being able to use the evidence in court, and it allows to see who tampered with evidence, if any tampering or mistreatment occurred. .

The 4th ammendment

Protects against unreasonable searches and seizures. If investigators violate these rights to acquire evidence, that evidence will not be usable in court.

Are there circumstances when police can search without a warrant?

Yes. Police can search if they have probable cause, or if someone is injured, police can go inside to assist.

What is a crime scene? Is it always a physical "place" or large area? When is it not?

A crime scene is any physical location where a crime has occurred, or is suspected of having occurred. It's not always a physical place. There can be a secondary location where additional evidence related to the crime is found.

If you are the first officer on the scene, what are your priorities and responsibilities?

Prevent anyone inside of the crime scene and ensure the body is preserved.

List some things an officer might do to ensure that the crime is preserved and secured.

Block off the crime scene and the body/evidence, place guards in front of the scene.

List some responsibilities of the lead crime scene investigator.

Document evidence, talk to witnesses.

What is the correct order a crime should be processed?

Conduct preliminary survey, photograph evidence, collect evidence, and reconstruct scene,

The 7 S's of crime scene investigation

Secure the scene Separate the witnesses Scan the scene See that the Crime Scene Investigators get photos Sketch the scene Search for evidence Secure the evidence

What are the two types of crime scene sketches and how are they different?

Rough sketch includes all items found at the scene, while a final sketch includes only the important items at the scene.

What are some features that a crime scene sketch should include?

Exact measurements, evidence, the body, and murder weapon.

What is the difference in analysis, comparison, and evaluation?

Analysis is studying evidence. Comparison is comparing evidence. Evaluation is deciding what evidence is more important.

How is the scientific method used in forensics?

It is used to test evidence, find out what occurred at the scene, and find who committed the crime.

Physical evidence

Any material object found at the scene. Blood, weapon, fingerprints, etc.

What is the difference in direct and indirect evidence?

Direct evidence is direct proof of a fact, while indirect evidence is circumstantial.

What are the 4 basic search patterns used by investigators?

Spiral Grid Quadrant Linear

Trace evidence

Small but measurable amounts of physical or biological material found at a crime scene.

What is the difference between means, motive, and opportunity?

Means is the ability to commit the crime. Motive is a reason to commit the crime. Opportunity is the chance or availability of resources for the crime to be carried out.

What is the difference between class evidence and individual evidence? How is each useful in forensics?

Class evidence only shares common characteristics, while individual evidence has a common origin.

What are the 4 ways evidence can be classified?

Demonstrative Real Testimonial Documentary

Individualization

A finding that a particular print or marking was produced by a particular source. It allows scientists to see that evidence came from one particular source, separate from all other kinds on the planet.

Frye V. United States

The jury decides if the evidence can be entered into the trial.

Miranda V. Arizona

Created Miranda rights.

Daubert V. Dow

The judge decides if the evidence can be entered into the trial.

Mincey V. Arizona

A trial in which the verdict affirmed that search warrants must be obtained if there is reasonable time to obtain them.

Dr. Henry Faulds contributed...

The use of fingerprint impressions.

Mathieu Orfila contributed...

Chemical analysis.

Alphonse Bertillon contributed...

Photography to document a crime scene.

Sir Alec Jeffreys contributed...

Forensic DNA fingerprinting.

Sir Francis Galton contributed...

Fingerprints are a reliable method of identification.

What is the difference between an infraction, a misdemeanor, and a felony?

Infraction- Least serious crime; speeding, parking overtime Misdemeanor- Minor crime; shoplifting, trespassing Felony- Major crime; murder, rape