Processing a Crime Scene Protocol for the Crime Scene Unit

What is a protocol? a detailed plan or procedure established by law enforcement. must be implemented for evidence to be admissable in court.

Processing a Crime Scene 7 S’s of Crime Scene Investigation 1) Securing Scene 2) Separating 3) Scanning 4) Seeing 5) Sketching 6) Searching 7) Securing Evidence

Securing the Scene Responsibility of the first responder Priority #1 = everyone’s safety Priority #2 = preservation of evidence Maintain a log of who enters the crime scene Request experts to scene if necessary Medical examiner Bomb squad

Is a dead body present? If so, before the CSI unit starts their work, the Medical Examiner (Coroner) takes over. Confirms that the body is dead. Preliminary determination of the postmortem interval (PMI) - time since death. Photograph the body and protect/collect all trace evidence. Transport the body to the ME lab.

Separating Witnesses Witnesses shouldn’t compare their accounts of the event. Avoid collusion – working together to create a story Asked basic questions: When did the crime occur? Who called it in? Who is the victim? Can the perpetrator be identified? What did you see happen? Where were you when you observed the crime?

Scanning the Scene Determine where photos need to be taken Determine if there is a primary and secondary crime scene

Seeing the Scene Photograph the overall crime scene Close-up photos with a ruler

Crime Scene Photos

Sketching the Scene Accurate rough sketch, including a body (if present) and all other evidence All objects measured from 2 fixed (immovable) points Label north Drawn to scale, which needs to be included on sketch. Transferred to computer program back at the station

Crime Scene Sketch

Searching for Evidence Search pattern is determined Look for things out of place Common things: fingerprints, blood, hair, fibers, semen, weapons, drugs, etc. No such thing as too much evidence. As investigation proceeds, they will decide if the material is actually evidence. Once located, but before collected, exact location must be documented.

Search Methods

Securing & Collecting Evidence All evidence needs to be properly packaged, sealed and labeled. Liquids & arson remains – airtight, unbreakable containers. Moist biological evidence – breathable containers (so they don’t mold) Once dry, evidence is packaged in paper bindles, then placed in plastic or paper bags. Control samples must be obtained. Chain of Custody needs to be maintained!!!!

Securing & Collecting Evidence Evidence Log: Case # Item inventory # Description of evidence Name of suspect Name of victim Date & time of recovery Signature of person recovering evidence Signature of any witnesses present during collection

Authentication of Evidence Chain of Custody-A record of who is in possession of the evidence from the time it is collected until the time it is delivered to the court. Must be uniquely identified. Packaged in tamper-evident packaging Packaging must be designed to preserve the evidence.

The End