Forensic Science Basics

Basic Understanding of Forensics

  • Forensics relates to applying scientific principles to criminal investigations.

Crime Laboratories

  • Federal Crime Laboratories:
    • Operated by federal government agencies, handling large scale or federal-level investigations.
  • State and Local Crime Laboratories:
    • Operate independently or as part of state agencies to assist in local criminal cases.

Expert Witnesses

  • Individuals with specialized knowledge or expertise in a particular area, who can provide testimony in court concerning that expertise.

Crime Scene Investigations (CSI)

  • CSI Overview:
    • Each person entering a crime scene brings unique elements (e.g., fingerprints, hair).
  • Photography:
    • Critical for documentation and later reference, including both wide shots and close-ups of evidence.
  • Crime Scene Drawing:
    • Involves sketching the layout of the scene, marking the positions of evidence.
  • Final Drawing:
    • The professionally drafted drawing is used as evidence in court.

Crime Scene Protocol

  • Protocol:
    • The essential steps that investigators follow upon arriving at a crime scene:
    1. Secure the Scene:
      • Ensure the area is safe; restrict access to unauthorized individuals.
    2. Record the Scene:
      • Document the scene through photographs, sketches, and detailed notes to capture the environment and evidence accurately.
    3. Collect Physical Evidence:
      • Carefully gather and package physical items that may be relevant to the case for further analysis.
    4. Maintain Chain of Custody:
      • Document every person who handled evidence to preserve its integrity and credibility in court.
      • Each piece of evidence is tracked from the crime scene to the crime lab, ensuring accountability.
  • Sign-off for Evidence Collection:
    • Upon delivering evidence to the crime lab, investigators must sign off, indicating which items were collected and ensuring proper record-keeping.