Crime Scene Investigation ( CSI )

CSI Basics

Crime scene investigation is the meeting point
of science, logic and law. "Processing a crime
scene" is a long, tedious process that involves
purposeful documentation of the conditions at
the scene and the collection of any physical
evidence that could possibly illuminate what
happened and point to who did it. There is no
typical crime scene, there is no typical body of
evidence and there is no typical investigative
approach.

At any given crime scene, a CSI might collect
dried blood from a windowpane -- without
letting his arm brush the glass in case there
are any latent fingerprints there, lift hair off a
victim's jacket using tweezers so he doesn't
disturb the fabric enough to shake off any of
the white powder (which may or may not be
cocaine) in the folds of the sleeve, and use a
sledge hammer to break through a wall that
seems to be the point of origin for a terrible
smell.

Who's at the Scene?

Police officers are typically the first to arrive
at a crime scene. They arrest the perpetrator is
he's still there and call for an ambulance if
necessary. They are responsible for securing
the scene so no evidence is destroyed.

The CSI unit documents the crime scene in
detail and collects any physical evidence.
The district attorney is often present to help
determine if the investigators require any
search warrants to proceed and obtain those
warrants from a judge.

The medical examiner (if a homicide) may or
may not be present to determine a preliminary
cause of death.

Specialists (entomologists, forensic scientists,
forensic psychologists) may be called in if the
evidence requires expert analysis.

Detectives interview witnesses and consult
with the CSI unit. They investigate the crime by
following leads provided by witnesses and
physical evidence.