To fume or not to fume?

[Veronica Rauch]

Sorry for double posting, I was interested in finding out what other agencies procedures are for fuming tape. Additionally, I wanted to ask if anyone has studied whether or not superglue fuming has an adverse effect on the development of latent prints from adhesive surfaces? Any recommendations on existing literature on this topic would be extremely helpful. Whew! I think I maxed out the quota for asking for help today! Thanks!

[Heidi Fraser]

Our agency allows a fair amount of discretion for this case, but what I personally generally do is remove the tape from whatever it was stuck to, stick it (the tape) to a piece of acetate, and fume it that way. In other words, I am only fuming the non-adhesive side of the tape. I then powder the non-adhesive side of the tape, then remove the tape from the acetate to process the sticky side separately (I personally use WetWop, although our lab has several suspension methods available from which to choose).

I hope that helps.

[firechem98]

I work in an Arson Lab. We get a fair number of incendiary devices with an ignitor of some sort, taped on the devices. What I have been doing is firest, fuming the outside wrapped with tape. Then cooling or freezing the item to release the tape and process the adhesive side with sticky-side powder. It seems to work very well. The number of prints found on the sticky side, usually far outweigh the number found on the exposed outside surfaces.

Good luck, Terry

[Andrew Schriever]

Does anyone use Undo to remove tape from the surface that it is stuck to? If so, how have your results been compared to freezing the tape to remove it?

I know that some studies have been done that show that it doesn't affect latents on adhesive surfaces, and I have done tests with mock evidence that worked ok. But I haven't had very good luck on the couple of times I have used it on evidence.

As to the original posters question,

My SOP calls to fume the tape in situ and process the exterior surfaces for latents, then to remove the tape and process the sticky side with stick side powder, wetwop, and/or gentian crystal violet. I am not a fan of wetwop as it has a little thicker consistency than I like, so usually I will process with GCV followed by stick side powder depending on the type of adhesive surface I am processing.

[Heidi Fraser]

We use UnDu to remove tape from surfaces. It depends on the surface, because often the tape can be easily removed without the use of UnDu. But if the adhesive is clinging stubbornly, or if it is stuck to paper, which often comes up with the tape, I will apply UnDu to get the adhesive to release cleanly.

I understand your hesitation -- I myself sit there watching the tape peel off of paper (or another surface) and get nervous, thinking there is no way any latent prints that were present will survive this abuse. Then I go apply the wetwop, and voila! Beautiful prints. Of course, there are times when you won't get good results on tape with or without UnDu. But I've used it successfully enough times that I trust implicitly that the UnDu is not having a deleterious effect on the evidence.

Incidentally, in my personal experience, I still get nervous using UnDu with duct tape... that adhesive is so gooey (pardon the technical jargon *grin*) that I have a hard time believing that it can "bounce back" from the UnDu process and I have not had notable success with it as of yet. But that could be just me. The UnDu/Wetwop combination has been a great success for me with pretty much every other type of tape I've done.

Heidi