Ch 2 Forensics

Where does forensic science begin?

At the crime scene

Any and all objects that can establish that a crime has been committed, provides a link between a crime and its victim, victim and perpetrator, and perpetrator and crime.

Physical Evidence

Securing and isolating the crime scene is the responsibility of whom?

1st arriving officer

First priority at a crime scene is to obtain what and?

Obtain medical assistance and arrest any perpetrators

What else must be done to secure the crime scene?

• Preserve and protect the crime scene

• Isolate and exclude all unauthorized personnel from the scene

• Determine boundaries

Who is in charge of the crime scene?

Lead investigator/detective

What are the responsibilities of the lead investigator?

• Evaluates the area

• Determines the boundaries of the crime scene

• Establish the perpetrators path of entry and exit

• Examine and document the entire crime scene

List the 3 ways that we record a crime scene

• Photography/video

• sketches

• notes.

The crime scene should be _____________ as completely as possible.

photographed

Documentation done by the CSI, regardless of artistic ability?

Rough Sketch

Drawn with aesthetic appearance with the aid of templates and drafting tools by a skilled person.

Finished Sketch

Constant activity while investigating a crime scene

Notes

_____ _____ must be collected and stored to preserve its integrity for forensic analysis.

Physical Evidence

Search for evidence at a crime scene must be what?

Thorough and systematic

Who collects evidence at the crime scene?

CSI or trained officers/personnel

Do we need a forensic scientist at the crime scene?

No

Why should one person supervise and coordinate the search at a crime scene?

Eliminates confusion and duplication.

What are the 4 methods used to search a crime scene?

Strip/Linear, Grid, Quadrant, Spiral.

Who are the members of the crime-scene investigation team?

Police Officers, District Attorney, Crime-Scene Investigators, Medical Examiners or Coroner, Detectives, Specialists.

How do we secure and collect physical evidence?

Physical evidence must be processed in a way that prevents any change from taking place between the time it's removed from the crime scene and the time it's received by the crime laboratory. The integrity of evidence is best maintained when it's kept in its original condition as found at the crime scene.

What are we trying to prevent when we collect physical evidence?

Contamination, breakage, loss or misplacement

Why must the chain of custody be maintained when handling physical evidence?

Continuity of Possession

______ of evidence is best maintained when it is collected in a way to keep it in the condition it was in when found at the scene.

Integrity

_________ is physical evidence whose origin is known from a suspect that can be compared to evidence obtained from a crime scene.

Standard Reference Sample

Packaging evidence separately prevents damage through contact and prevents what?

Cross Contamination.

What must be worn while collecting evidence?

Gloves, mask, Tyvek suit, shoe coverings

Swab of the inner portion of cheek (collected to determine the DNA profile of an individual).

Buccal Swab

What is used when there is potential for dust, mist, or splash to face/eyes?

Mask or respirator

What color bag should bio hazardous materials be placed in?

Red

Removal of evidence from a person must be done in conformity with which amendment?

4th Amendment

Who can issue a search warrant?

Judge, magistrate, or judicial official.

What is a coroner & what do they do?

Elected official. No medical training required. Identifies the body. Signs the death certificate.

What is a medical examiner & what do they do?

Medical doctor. Usually trained to be forensic pathologists. Perform autopsy and determine cause & manner of death.

What are the 7 S’s of crime scene investigation?

1. Secure the Scene

2. Separate the Witnesses

3. Scan the Scene

4. See the Scene

5. Sketch the Scene

6. Search for Evidence

7. Secure and Collect Evidence.