CSI Tips

Lab Requests

  • Clearly describe the location of the evidence
  • Lab processing can continue through the interview phase
    • Search warrants
    • DNA comparisons
    • Fingerprint comparisons
    • Handwriting


  • Swab the object, send the swab to the lab, not the object
  • If there is blood on the clothes then remove to look at more closely during processing
  • When the lab results state there are not DNA matches remember to ask for a comparison to the victim, and if that doesn't match then ask suspects for samples, get a search warrant if they refuse. (Must have probable cause)
  • Check to see if DNA that doesn't have a match on file is a match to other DNA found at the scene.

Autopsy Report

  • Only information that will be provided is the time and cause of death
  • Need to make specific requests to get more information

Hair samples

  • Root will be needed for analysis of DNA comparison


  • Students can ask for trajectory

Information about the victim

  • Basic information about the victim can be asked during the processing phase


  • Keep an open mind about what happened, don't get tunnel vision
  • Practice knowing when to Mirandize and make sure that the suspect understands his/her rights
  • Remember to ask for basic information: Date of birth, age, height, SS#
  • Ask for an alibi, then verify that it checks
  • Determine what to charge the suspect with
  • Maintain a timeline of events, and how the suspects' stories fits to the timeline
  • Ask suspect if they were at the scene of the crime and if they committed the crime