CLPEX Chat Board

I have a piece of evidence that the officer luminoled (doh!) before submitting to the lab for processing (yes, it doesn't make sense). Before I begin processing, I am wondering if there are any ill-effects that luminol has on processing techniques such as amido black, acid yellow 7, DFO, or cyanoacrylate/dye stains. I haven't opened it, yet, so I'm not sure what my route is going to be, but I'd like to first know what my options are after the "luminol incident." I'm really not all that familiar with luminol since we don't use it in our lab. Thanks!

Doh!!! is right. A lab in which I previously worked had a policy that they did not rexamine evidence already processed by somebody else. You want us to process it, you send it in clean. You process it first, you answer in court for what you did, but we don't try to pull your chestnuts out of the fire for you. That always seemed like a good policy. Once the officer has screwed it up, we can't unscrew it for him.

Good luck on this one!

We just adopted a policy where it is "at the Criminalist's discretion" as to whether they process pre-processed evidence, so I can pick and choose depending on how many pieces they submitted, how easy it is to correct/recover from what they did, how long it will take in the lab, etc. Since this is a homicide and the only piece submitted for fingerprints, I'm going to do what I can to get something. I will, however, be making some phone calls about how experimenting with chemicals is not a good idea on homicide cases....or really any case you plan to solve.

Maybe try and put some test prints on a similar surface, luminol it and try a few techniques. I don't think luminol is destructive to anything per say beyond the fact that it is aqueous , but that alone might be enough to screw up the chance of getting anything useful. Look on the bright side - anything you do get off the item now is a bonus!!

Thanks, Kevin. Unfortunately, I do not have luminol on hand and have never used it. I opened the item and the luminol has definitely left behind some crustiness/moisture residue and there is no visible blood. I'm leaning towards acid yellow 7 because then I can use the prewash to get rid of some of that crustiness and fix the prints (or what is left of them) at the same time?? I'm not too worried about destroying anything. I think someone else already took care of that. I'll sit on it for another day before I get started.

I'm not too worried about destroying anything. I think someone else already took care of that.

Lol!

AY7 sounds like a good choice with the pre-wash..good luck!

Hi Michelle Waldron,

First read this article on this forum; New.Chem.improvement or Shoe and Fingerprints with blood.

Then you get answers to your questions after Luminol.

Theo Velders

Great paper. Thanks, Theo. Acid yellow 7 is the only process we have validated at this point in time, but I may validate Hungarian Red so we can use that, as well. I will also get a hold of some gel lifters if I don't have any. The sad thing on my part is that this article was on my "to read" pile, which is turning into more of a mountain than a pile.