Steps to a Homicide Investigation
1. Secure the Scene
The responsibility of the first officer at the scene of a
crime is to preserve its integrity until the patrol supervisor
can arrive. The supervisor - a sergeant or lieutenant - must
ensure that the crime scene is preserved. Responsibilities of
patrolmen include surrounding the area with police tape,
controlling crowds, and preventing overzealous members of the
media from destroying or removing crucial evidence.
2. Find Eyewitnesses
Although eyewitness testimony is not always considered 100%
accurate, finding such witnesses is the patrolman's foremost duty
once the crime scene is preserved and patrol supervisors arrive
on the scene. Patrolman must get the names and addresses of any
people in the area, and have them wait to speak with the
detectives, upon their arrival.
3. Photograph the Crime Scene
When the detectives arrive, their first job is to photograph
the crime scene. Their work is monitored by their own detective
supervisors (who are detective sergeants or detective captains).
Several photos must be taken of the crime scene:
- Shots from the 4 different corners of the scene
- Long distance shots
- Medium distance shots
- Close-up shots of the body and any evidence
- Other relevant details
4. Search for Latent Prints
Fingerprinting at a crime scene is referred to by police officers as searching for latent
prints. Only detectives are qualified to dust for prints. Among the most likely targets for fingerprinting are
weapons, points of entry or exit, and tabletops. The exact fingerprinting process is described below in greater detail.
5. Gather Evidence
Detectives can be looking for details as subtle as footprints or items as small as
clothing fibers, hair strands, blood samples, or
paint chips. Such "trace evidence" is manipulated through tweezers and other instruments appropriate for dealing with
objects of such minute size or substance. It is then transferred to a slide and sent to a forensics lab for examination. Larger items, such as weapons, are handled only while
the officer is wearing gloves and are deposited in a plastic bag. Whenever evidence is
gathered, the name of the detective who found and returned it
to the police station is carefully recorded. The name of the
police officer who received it at the evidence locker at the
local or county police station is also noted. This is called
the "chain of evidence," and is used to ensure the reliability of
evidence at trial.
6. Remove the Body
By this time, the county coroner has arrived. The coroner must make
examinations of several things, including the lighting,
temperature, humidity, and weather in the area, in order to later
establish time of death to a greater degree of accuracy. The
body will be taken to the county morgue, where an autopsy is
performed, revealing (usually) the cause of death.
There are several different types of fingerprint powders; a
fingerprint might only show up when a certain type of powder is
- black - for use on paper
- white - for use on black items
- silver - for general use
- metallic - for use on metallic items
No two persons' fingerprints are exactly alike. Fingerprints will not
come out clearly on porous material. To search for latent prints, a detective will use an ostrich
feather fingerprint duster to apply the appropriate color(s)
powder from the container to the area. He or she will then,
in a rapid, circular motion, twist the duster to spread the
powder over the area. When a potential fingerprint is revealed by
the powder, a special strip of tape can be used to
actually "lift" the fingerprint from the object. This tape can
then be examined by fingerprint experts and compared to prints
stored on local, state, and federal crime computers.
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Graphical bars used with permission and taken from the CD-ROM accompanying the Que Corporation book Using HTML by Tom Savola.
All pictures were taken by Detective Sergeant Stephen Wilde for use in this project.