Jeff,

Someone else asked about this and I PM'd the following:

Don't worry about collecting evidence. If you are helping on a SAR let the pros do it. It has been since 1995 that I could call myself a "pro". When I go help on SAR (mostly Alzheimer's folks), if I find a need for evidence collection I mark the area for scene protection and call for help. There are tons of issues about "chain-of-custody" and evidence contamination that can really screw up a criminal case. You don't want to mean well and find out it cost a piece of evidence to be inadmissible in a court of law.

Is that along the lines you were thinking of?
_________________________
I do the things that I must, and really regret, are unfortunately necessary.

RIP OBG