(2) Setting fixed and/or roving patrols.
Such protection not only preserves the integrity of the evidence; it also
denies access to the scene to unauthorized persons.
b. When first aid is necessary, evidence takes second place.
scene may be disturbed to evacuate injured personnel, or to have persons move
evidence when aiding the injured. If so, the position of the evidence should
be marked or outlined.
Nevertheless, careless or reckless actions should be
avoided at a crime scene to minimize the movement of evidence.
c. Evidence may be destroyed or altered by rain, snow, fire, or other
causes before processing can be completed. Therefore, appropriate protective
actions must be taken. For example, a raincoat or a piece of canvas may be
used to cover impressions in soil which are exposed to rain; a wooden or
pasteboard box may be placed over impressions in snow. Items which will melt
should be shielded from the sun or other heat sources; items such as food and
blood should be covered to protect them against contamination by insects or
d. Protection of a crime scene is of great importance. Protection is a
continuous process. It lasts until you have thoroughly processed and released
the crime scene.
4. Photographing the Scene.
Photographs are made at the crime scene to
supplement notes and sketches. They are used to clarify written reports and to
provide a permanent record of perishable or fragile evidence.
provide identification of personnel at the scene.
a. The most important rule in crime scene photography is to photograph all
evidence before anything is moved or touched.
Fingerprints are photographed
before lifting them.
b. When feasible, an object is photographed from different angles. This
ensures complete coverage. Care is required, however, to avoid angles. These
would cause a distorted image, and not produce a true picture of what is seen
by the naked eye.
c. Evidence flags are useful in marking the location of small items of
evidence for a photo.
d. Investigative personnel should not be photographed in the scene.
e. Notes should be made concerning the time of the day the photograph was
Note also the types of cameras, lens, and film used.
settings to include aperture and shutter speed.
Record the distance from
camera to subject as well as the height of the lens above the ground.
camera positions are shown on the photo exactly for this purpose. Photos taken
at a crime scene may be studied later to find clues previously