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THE BASICS OF CSITo understand what happens at a typical crime scene investigation, it’s important to understand a few basic elements:

The Purpose of CSI …• Determine if a crime has

occurred• ID the victim(s)• ID the suspect(s)• Collect evidence related to

the crime

• Re-enact the events of the crime

• Link suspect, victim & crime scene

The Basic CSI Tasks …Protecting & searching the sceneEvaluating the scene & evidenceDocumenting the scene & evidencePreserving & collecting evidence

CSI

Protecting & searching the scene, documenting & scene and evidence, and preserving & collecting the evidence are all considered the mechanical aspects of CSI.

Evaluating the scene & evidence is considered the thinking aspect of CSI.Ideally, a crime scene investigator should be thinking (evaluating) at all times while conducting the mechanical aspects of CSI; but it is all too easy for a crime scene investigator to fall into the trap of working mechanically … especially at a large/complex crime scene containing dozens or even hundreds of evidence items.

The Basic Premise of CSI …It is impossible for suspect, victim and crime scene to come together — usually in a violent manner — without the transfer of physical (trace) evidence.It is this premise that ensures investigators that a careful investigation of a crime scene is worth the effort. The evidence will be there; it just has to be found and carefully/properly preserved and collected.

The Inherent Problem of CSI …Every investigator (or EMT, reporter, neighbor, etc.) who enters the scene has the potential to damage evidence and leave or pick up trace evidence.In effect, a CSI cannot expect to enter a crime scene without adding to or subtracting from the available evidence. The trick is to be thoughtful, careful and persistent.

HOW TO DETECT A POLICE INVESTIGATOR FROM A CRIME SCENE INVESTIGATOR

The Crime Scene Investigator is typically (and there's a lot of variation here among federal, state and local jurisdictions) an unarmed, non-sworn (not authorized to enforce laws or arrest suspects) and non-scientific-degreed technician whose primary job is to:

respond to routine crime scenes

collect basic information from the first responding officer at the sceneset a scene perimetertake a set of "over-all" photos from outside the scene perimeter looking inmake a quick search for potentially perishable evidencetake a set of "over-all" photos inside the scene perimetermake a careful and methodical search for items of physical evidenceproperly document, preserve and collect those items of evidence

INSTRUCTOR’S MASTERCADET HANDOUT

STORY PROMPT

Genius Notes

JOT DOWN NOTE FOR INCLUDING YOUR OWN KNOWLEDGE OR EXPERIENCE

make a scene sketch that includes the location of all evidence itemspackage and tag the evidence itemstransport and transfer custody of the evidence to the crime lab

The Detective is typically an experienced, armed and sworn law enforcement officer whose primary job is to interrogate witnesses and suspects, and utilize information and physical evidence found at the scene (and, ultimately, analytical reports regarding that evidence) to locate, arrest and assist the prosecutor in bringing the alleged perpetrator before the courts.