Protection
The best form of preservation is first to photograph it in situ or where the object is first located, and then take the object which shows key traces, protect it and analyse later under controlled laboratory conditions.
Many different techniques are used in the protection of trace evidence from criminal investigations, although all must be photographed when fresh and still in place. Samples may be collected by shaking, brushing, taping, vacuuming, swabbing and hand picking, although great care may be needed to prevent contamination with other substances (such as natural oil and sweat on the hand of the collector). In some cases, such as with oil or grease, a solvent extraction can be used to collect the evidence for analysis. The method used for collection is generally dependent on both the type of evidence and from where or what sort of object it is being collected.
Trace Evidence is also found in much smaller amounts at crime scenes.
Read more about this topic: Trace Evidence
Famous quotes containing the word protection:
“As Jerome expanded, its chances for the title, “the toughest little town in the West,” increased and when it was incorporated in 1899 the citizens were able to support the claim by pointing to the number of thick stone shutters on the fronts of all saloons, gambling halls, and other places of business for protection against gunfire.”
—Administration in the State of Ariz, U.S. public relief program (1935-1943)
“We all cry out that the world is corrupt,—and I fear too justly,—but we never reflect, what we have to thank for it, and that it is our open countenance of vice, which gives the lye to our private censures of it, which is its chief protection and encouragement.”
—Laurence Sterne (1713–1768)