|Posted on Wednesday, May 15, 2002 - 02:22 pm: ||
I have had a similar problem recently. I contacted the FBI and they recommended CA fuming followed by a dye stain. They had recently worked a similar case and said the blood (if it was reasonably fresh) had absorbed the dye stain thus fluorescing with their light source. I tried that and it did not work as suggested. However, additional detail was developed by using Lightning Powder's BLITZ GREEN magnetic powder. It should be noted that the use of this powder required clean up with a squirrel hair brush in order to visualize the additional detail. In addition, the fluorescent capability of this powder was of no use during my examination. The ridge detail present was visualized with lighting from an MP-4 stand and digitally enhanced.
|Posted on Friday, May 10, 2002 - 02:40 am: ||
You have a little problem with this situation but not without solutions. The textured surface of the Glock makes it a difficult substrate but I am assuming that the latent is lying in such a way that the human eye can visualise it! One technique that can resolve the problem is RUVIS (reflected ultra violet identification system). Please try this on a control sample and not the exhibit. The reflected UV at 254nm is gathered into a digital intesifier (Crime Site scope - Sirchie product). The resultant image off the scope is then transferred into a digital camera and recorded. The beauty of the technique is that it is non destructive,quick and highly sensitive. The down side is that it requires the position of the UV light to be constant once the correct angle is obtained, and it involves the recording of the image using digital photography. If the substrate has a uniform background texture and still prevents RUVIS from producing the result, then consider doing some post capture enhancements using fourier transform or other digital techniques.
Another method would be to consider Luminol reagent but once again try this on a control sample first. Luminol works best on prints that have aged, dried and thereby providing the best sample for the reaction. If neither of these work I will ask a couple of our scientists as this subject is important for our organisation who use Glocks as issue firearms. Regards. Les Bush
|Posted on Thursday, May 09, 2002 - 08:06 pm: ||
I tried to answer off-line, but no address for Andrew Reinholz. Even though it is a black plastic surface, you might try UV illumination. Blood can absorb UV, making it appear black(er) while 'softening' the roughness of the surface. Differences in degrees of black may make the latent visible enough for photography.
If you can be patient, there is something else that is still in experimental development at Lightning Powder Company. You can contact me at my e-mail address for more information.
|Posted on Thursday, May 09, 2002 - 02:29 pm: ||
Any ideas about processing a "suspected" bloody print from the rough area of a Glock? (black Plastic)
Thank You for any ideas.