Investigator G. Nome’s Fabulous Guide to Developing Fingerprints

Confused as to which fingerprinting medium is right for the task at hand? Well, Investigator G. Nome has assembled the ultimate guide for the heroes of your tall tales, and he recommends keeping it within easy reach.

Heroes such as Harry Bosch, Jack Reacher, D.D. Warren, Will Trent, or any of their peers, will never again fret over such details.Actually, the creators of those characters—Michael Connelly, Lisa Gardner, Lee Child, and Karin Slaughter—attended training classes at the Writers’ Police Academy to help their protagonists enhance their crime-solving abilities.

The icing on the cake is that many fingerprinting classes at the Writers’ Police Academy are taught by the pros from Sirchie (formerly Sirchie Fingerprint Laboratories). Sirchie manufactures fingerprinting powders, lifters, and a wide range of evidence testing and collection equipment and, well, the list of Sirchie’s products is practically endless. Other printing sessions are taught by CSI experts.

The Writers’ Police Academy and Sirchie partnered to present the unique event, MurderCon.

Anyway, here’s the scoop on processing prints.

Investigator G. Nome’s Guide to Developing Fingerprints

Before attempting to lift a print from any surface, the savvy investigator will first determine the type of surface to be printed. In addition to surface type and texture (porous, nonporous, etc.), other factors must be considered, such as the presence of foreign matters—dust, dirt, perspiration, blood, oils, grease, and moisture, to name a few.

Lighting is important, including the use of alternate light sources and lasers. The latter two can cause the perspiration and oils in found in some prints to fluoresce, making them easy to see without further developing.

Once investigators have determined the surface type and whether obstacles exist (foreign matter) it’s time to select the proper method and materials needed to properly develop the desired prints(s).

Surface Types

As always, the first order of business is to try and see the prints using only the naked eye. Sometimes they’re quite obvious.

Porous Surfaces – first attempt the naked eye approach. If no prints are obvious, then try fluorescence by laser or alternate light source. If that doesn’t quite work, then it’s time to bring out the big guns, such as…

1. Iodine fuming

2. Ninhydrin

3. DFO (1,8-Diazafluoren-9-one)

To learn about Iodine fuming and Ninhydrin, please click here to read my article “Ninhydrin and Iodine Fuming.

Non-Porous Surfaces – again, try the naked eye. If no prints are obvious, then try fluorescence by laser or alternate light source. If those steps do not produce results, then use the following to develop invisible prints.

1. Cyanoacrylate fuming (SuperGlue)

2. Cyanoacrylate dye

3. Vacuum metal deposition (VMD)

4. Powder

To learn about developing prints using SuoerGlue, please click here to read my article “Cyanocrylate Fuming – Fingerprinting with Superglue”

Still not satisfied with your options? Okay, let’s call in the specialists …