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:
“Guns have metamorphosed into cameras in this earnest comedy, the ecology safari, because nature has ceased to be what it always had been—what people needed protection from. Now nature tamed, endangered, mortal—needs to be protected from people.”
—Susan Sontag (b. 1933)
“After so many historical illustrations of the evil effects of abandoning the policy of protection for that of a revenue tariff, we are again confronted by the suggestion that the principle of protection shall be eliminated from our tariff legislation. Have we not had enough of such experiments?”
—Benjamin Harrison (1833–1901)
“What is marriage, is marriage protection or religion, is marriage renunciation or abundance, is marriage a stepping-stone or an end. What is marriage.”
—Gertrude Stein (1874–1946)