After processing the major, obvious evidence, search for and collect trace evidence. After the trace
evidence has been processed, the scene should be dusted for latent prints. If latent prints are found,
they should be photographed and collected. After the latent prints are lifted, explore the scene for trace
evidence that was not observed during the visual search. Pieces of evidence found during the
exploratory search should be noted, photographed, sketched, and collected. When sweeping or
vacuuming, surface areas should be segmented. Package the sweepings from each area separately.
Record the location of their point of recovery.
Make elimination prints of investigators and all other persons who may have had access to the crime
scene. Elimination prints allow the lab to eliminate the prints of all persons who had legal access to the
scene. Usually, elimination fingerprints and physical evidence standards are collected after you
complete the above actions.
When collecting evidence at the crime scene for lab analysis, the amounts needed will depend on the
nature of the evidence and the tests to be conducted. For proper evaluation of stains by lab technicians,
submit control samples in addition to the collected stains. For example, a stain on soil or porous
surfaces is collected by dipping or gouging beneath the stain. Also, unstained portions are collected and
identified as control samples. Preserve the integrity of control samples as carefully as you do the
integrity of evidence.
As you begin your efforts to process evidence, remember that the evidence value of materials of the scene is
not always easy to tell in the early stages of an investigation. If you have any doubt about whether or not to
collect and preserve an item that only might be evidence, do so. Collect and preserve glass fragments, for
example, even if you are unsure they will be useful. If you do not, the broken glass is likely to be discarded as
Use care with doors, windows, and other openings with hinged or sliding doors or covers. They must not
be opened, closed, or handled in any way that would destroy or mar minute tool marks or fingerprints. In
handling a firearm, take care not to cause the loss of possible latent prints unless certain they will not be material
to the case. In most cases, weapons may be picked up by the grips. The checkering precludes getting usable
prints from this area. Or you may use a piece of wire or like material placed through the trigger guard or lanyard
ring. Do not use a handkerchief or like material or insert any object into the bore to pick up the weapon.
It is logical to start the search of a crime scene for fingerprint evidence at the point of entry. Check all
possible points of entry to see if futile tries may have been made there. A strong oblique light is a great aid in
finding latent fingerprints.
Check walls. When a person picks up a heavy object close to a wall, he may place his hand on the wall as a
brace. Look on counter tops and other flat surfaces where persons may lean, as well as looking on objects they