Trace Evidence Section

"Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool marks he leaves, the paint he scratches, the blood or semen he deposits or collects - All of these and more bear mute witnessagainst him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It cannot perjure itself; it cannot be wholly absent. Only its interpretation can err. Only human failure to find it, study and understand it, can diminish its value." (Crime Investigation , Kirk, Paul. L, New York : Interscience Publishers, 1953.)

The term "trace evidence" is generally thought of as any type of evidence occurring in sizes so small that it can be transferred or exchanged between two surfaces without being noticed. The first scientist to formally articulate a philosophical foundation for transfer-evidence occurrence was the Frenchman, Edmond Locard (1877-1966):

The dust and debris that cover our clothing and bodies are the mute witnesses, sure and faithful, of all our movements and all our encounters.

His postulate that objects or surfaces which come into contact always exchange trace evidence is known today as "the Locard exchange principle." Today the forensic community uses the term "trace evidence" to include associative-type evidence that is usually microscopic in nature. This evidence is used to show or substantiate contact between people, a person and an object, or between two objects (or places). The most common examples of this type of evidence are: fibers and textiles; paints and coatings; plastics and polymers; glass and hair. In addition to these services, the DOFS Headquarters Trace Evidence Section offers the examination of fractured materials and general materials.

One recommended method for packaging trace evidence is a pharmaceutical paper fold . The paper fold should then be sealed in an outer container such as a paper bag or envelope for submission to the laboratory