| Author | Message | ||
     Kathy Saviers |
The manufacturer of TapeGlo is: Lumachem, Inc. 8050 South 1300 West West Jordan, UT 84088 Tel 801-256-3322 FAX 801-256-3298 | ||
| David Wade |
Something you should definitely try on black electrical tape is Titanium Dioxide. I stumbled onto this process while at the FBI Academy last year and just wrote an article on it for the JFI. It develops prints on both sides of the tape and they are white, which obviously is good for black tape. E-mail me at DWade@cabq.gov and I will send you all the info. It works better than anything else I've seen. | ||
| Tina Bennett |
To Daryl and Ernie: Thanks so much for all of your help. It's greatly appreciated. Since we've been busy lately, I haven't had a chance to get back to the tape, but it's there, just waiting for me. We do have gentian violet, an alternate light source (both an Omnichrome Omniprint 1000 and a Blue Light Special), sticky side powder, and dye stain. However, I'm not familiar with the Tape Glo dye. Can you give more info on it? I'll definitely give one of these methods a shot and let you know what happens. Sorry for the delay sometimes in replying. Our Internet access here at work has a mind of its' own :-) so I never know if it will access a site or not. | ||
| Tina Bennett |
To Daryl and Ernie: Thanks so much for all of your help. It's greatly appreciated. Since we've been busy lately, I haven't had a chance to get back to the tape, but it's there, just waiting for me. We do have gentian violet, an alternate light source (both an Omnichrome Omniprint 1000 and a Blue Light Special), sticky side powder, and dye stain. However, I'm not familiar with the Tape Glo dye. Can you give more info on it? I'll definitely give one of these methods a shot and let you know what happens. Sorry for the delay sometimes in replying. Our Internet access here at work has a mind of its' own :-) so I never know if it will access a site or not. | ||
| Daryl W. Clemens |
I've had some success with the freezing method Ernie mentions. (I used liquid nitrogen to freeze duct tape). I also tried chemical methods to separate it, and found they didn't work very well. Freezing works fairly well if the tape is stuck adhesive to backing, and not nearly as well if stuck adhesive to adhesive. For latent processing you could try the new TapeGlo dye, or superglue the tape and use a flourescent dye stain. If you don't have an ALS, then gentian violet is an extremely good method, your only problem on black tape will be seeing a dark print on a dark background. Good luck. Daryl W. Clemens | ||
| Ernie Hamm |
The following was sent direct, but is posted for others: Tina, Not knowing what your unit has for latent processing, I'm not sure if the following information is of value. One way of separating black electrical tape is by freezing (I mean really freezing) the tape. Once the 'clump' is frozen, it can sometimes (these techniques are not always universal) be separated by then pulling the tape apart in quick tugs. Something to remember in this process. The latent processing technique selected for the adhesive side of tape is going to react to latent residue that has been retained in the adhesive matter of the tape. That is why heat, especially high heat, may not be the best course of action. Heat can melt the adhesive and destroy all latent print residue contained therein. The same is true of any adhesive release agents that will 'dissolve' the adhesive and thus its contents (latent prints). Freezing should not alter the adhesive, just make it brittle and allow it to be snapped apart. Many years ago I had good success with black electrical tape surfaces, both adhesive and non-adhesive, by using a crystal/gentian violet solution. True, this is a dark reaction, but you can see different shades of 'black' in this sort of treatment and the different shades can be photographed with proper lighting angles. Another thing to remember, while the separation of the tape may not be as clean as you want, there could be areas in the 'clump' that were not stuck together and which may retain useable latent prints. Before you try any processing techniques, make a visual inspection of all areas to see if visible latent prints have been impressed into the adhesive and if they can be photographically recorded prior to the application of any chemical method. Good luck. Ernie Hamm | ||
| Tina Bennett |
I have a clump of black electrical tape that was removed from the tampered stock of a sawed-off shotgun. I have been reading several pieces of material from not only the Journal of Forensic Identification, but the FBI, the Secret Service, and the International Association for Identification. I know from the past that sticky-side powder dosen't work well on electrical tape. Since the tape will need to be separated, I know there are several methods, including a blow dryer (which I've used with great past results), but as I don't want to cause damage to any possible prints, I'm not sure if I should try this, even on a low temperature. (One publication said that heat could possibly damage prints on the tape). Therefore I have a couple of questions. One: what is the best method for separating the tape? Two: the simplest method to develop possible latents on black electrical tape, hopefully using products currently on hand in our unit? |
