How should paint chips be collected to ensure preservation?

Using wooden tongs, tweezers, or forceps for collecting paint chips is the best practice to ensure their preservation. This method minimizes direct contact with the paint, which can help avoid contamination or alteration of the sample. Tools like wooden tongs are particularly advantageous because they reduce the risk of introducing oils or residues from human skin that could impact analytic results. Additionally, using these implements allows for more precise handling of small or fragile fragments, preventing destruction of the evidence.

In contrast, collecting paint chips with bare hands can compromise the integrity of the sample because skin oils or moisture may contaminate the paint. Swabbing paints, while useful in specific forensic contexts, may not capture the entire sample of the chip and could potentially alter its composition. Moreover, gloves do provide a protective barrier when handling evidence; however, they do not address the risk of mechanical damage that can occur with direct handling. Thus, the use of specific tools is the most appropriate method to preserve the integrity of paint chips in a forensic investigation.