Forensics

Forensics

1. Vocabulary

   • Crime scene
     • any physical location in which a crime has occurred or is suspected of having occurred.
   • Primary crime scene
     • the original location of a crime or accident.
   • secondary crime scene
     • an alternate location where additional evidence may be found.
   • suspect
     • person thought to be capable of committing a crime
   • alibi
     • statement of where a suspect was at the time of a crime
   • accomplice
     • person associated with someone suspected of committing a crime.

2. Types of evidence

   • Testimonial evidence
     • Includes oral or written statements given to police as well as court testimony by people who witnessed an event
   • Physical evidence
     • Refers to material items that would be present at the crime scene, on the victims or found in a suspects possession.
   • Trace evidence
     • physical evidence found in small but measurable amounts, such as strands of hair, fibres or skin.

3. What evidence can do for an investigation

   • may prove a crime was committesd
   • establish key elements of a crime
   • link a suspect with a crime scene or victim
   • establish the identity of a victim or suspect
   • corroborate verbal witness testimony
   • exonerate the innocent
   • give detectives leads to work with in the crime

4. Crime Scene Personnel

   • Police officers
     • responsible for securing the scene so no evidence is destroyed
   • CSI unit
     • document the crime scene in detail and collects physical evidence
   • district attorney
     • present to determine if a search warrant is required and obtains them from a judge.
   • Medical Examiner
     • may or may not be present to determine cause of death
   • Specialists
     • may be called in if the evidence requires expert analysis
   • Detectives
     • interview witnesses and consult with the CSI unit. they investigate to crime by following leads provided by witness and physical evidence

5. Protocol

   • 1. Interview
     • interview the first officer at the scene or the victim to determine what allegedly happened. gives investigators a place to start.
   • 2. Examine
     • helps identify possible evidence, identify point of entry and exit. identify the general layout of a crime scene
   • 3. Document
     • creating a pictorial record of the scene to demonstrate the layout of the crime scene and to identify the exact location of the victim and evidence.
   • 4. Process
     • process the crime scene for evidece, both physical and testimonial. the crime scene technicians evaluate and collect physical evidence from the crime scene for further analysis.

6. types of forensic study

   • drug chemistry
     • determines the presence of controlled substances
   • trace chemistry
     • identification and comparison of materials from fires, explosions, paint and glass.
   • Biology / DNA
     • analysis of bodily fluids and dried stains eg. semen, blood, saliva.
   • microscopy
     • microscopic identificstion and comparison of evidence
   • toxicology
     • tests bodily fluids and tissues to determine the presence of drugs and alcohol
   • Latent Prints
     • identification and comparison of fingerprints and other impressions from feet, shoes, ears, lips, or tire tread.
   • Ballistics (firearms)
     • study of bullets and ammunition through the comparison of fired bullets, cartridges, guns and gunpowder
   • Toolmarks
     • examines marks left by tools on objects at a crime scene or on a victim
   • Questioned documents.
     • examination of documents to compare handwriting and other characteristics that would help determine its origin