Latent Print Examination: "Tactical to Practical" Show

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Webservant

Posted on Wednesday, December 24, 2003 - 09:07 am:

The 23 Dec 03 History Channel show "Tactical to Practical" included about twenty minutes of me, your webservant, at the US Army Criminal Investigation Laboratory (USACIL) along with background details about technology discovered at USACIL, a cold case murder solved, etc. As Paul Harvey might say, "...and now, for the rest of the story."

In 1983, two boys playing in the woods near a cul-de-sac in their neighborhood discovered a freshly-dug hole in the ground and wondered why it was there. Later that same day the boys were caught breaking bottles with rocks in the cul-de-sac and their parents grounded them for a week. At the end of the week, the boys returned to the area to play and found that the hole was filled-in. They thought immediately that it must be buried treasure and started digging. After digging down several feet, they made the gruesome discovery of a body wrapped in black plastic garbage bags. They ran home and reported it. The boys had discovered the body of a teenage girl who had gone missing a week earlier, the same day that they were grounded.

Columbia County Sheriff's Department and Georgia Bureau of Investigation (GBI) investigators processed the crime scene and submitted evidence to the GBI laboratory. The plastic bags were processed with superglue fumes (I had something to do with helping that technology emerge in the 70s) and then dusted with contrasting colored powder by the GBI Laboratory (pretty standard techniques in 1983). GBI Laboratory exams revealed no identifiable latent prints.

A year later, in 1984, I was visiting a friend (Questioned Document Examiner Hans Gidion, retired from USACIL) on a Sunday afternoon in Augusta, Georgia when GBI Special Agent Jimmy Tarvin stopped by to chat. Tarvin asked me if I was a QD Examiner also and I explained that no, I was a Latent Print Examiner. He remarked that fingerprints had let him down in an important case a year earlier and he explained the black plastic garbage bags recovered from the cul-de-sac crime scene. I asked him if the evidence had been examined using laser technology and explained that the GBI Laboratory did not have laser equipment capable of performing such examinations.

Tarvin related that the evidence had not been examined by other labs, and he was interested in the Army Crime Lab helping. However, he was also concerned about additional fingerprints that may have been deposited on the bags by Serology Examiners and other GBI Laboratory scientists who examined the bags after latent print examination had been completed. I explained that any fingerprints that may have been deposited by other scientists on the bags (which would be unusual since most Serologists or other forensic scientists would wear gloves) would not interfere with detecting latent prints from the murderer(s) because the dye we use for such evidence is dissolved in alcohol which should wash away any “new” latent prints deposited after the plastic bags had been superglue fumed (the dye stain solution “tags” the superglue fumed prints but rinses clean the remainder of such nonporous surfaces).

The following week, Tarvin brought the plastic bags to USACIL and with the evidence still in his custody (for Posse Comitatus reasons). I processed the bags with Rhodamine 6G dye dissolved in methyl alcohol, then rinsed the excess dye stain from the bags with clean methyl alcohol and let the bags dry. Upon examining the bags under Argon ion laser (primarily 488 and 514.5 nm wavelength monochromatic light), excellent quality latent prints were easily detected. I contacted GBI Laboratory Latent Print Examiner Charlie Moss so he could join Tarvin and me at USACIL to observe the latent prints and be present during photography.

Using the resulting latent print photos of “glowing” latent prints from the garbage bags, the GBI Laboratory identified a suspect. They were made by one of the victim’s high school teachers, who had moved from Georgia since the murder and was teaching school in Texas. The teacher was found guilty of murder and given a lengthy prison sentence.

Latent Print Examiners viewing the Tactical to Practical show will immediately notice that the video images do not match the narration. The narration talks about a ninhydrin/laser technique (involving brown paper bags, cardboard boxes and other non-white porous surfaces) I discovered in 1981 and which was the “first reliable laser technique” for enhancing latent prints (at a time when inherent luminescence was the only laser exam method reported). In the fall of 1981 (in Sierra Vista, Arizona), I presented the first expert testimony in America involving latent prints that were identifiable only via laser examination and laser photography. Latent Print Examiner Louise “Mickey” Head of USACIL was the Latent Print Examiner who testified to the identification in Arizona and I presented the expert testimony involving the novel technology and the luminescence (absorption/emission) science behind it. The FBI’s “Crime Laboratory Digest” published my article (“You Are Missing Ninhydrin Developed Prints”) documenting the novel technique in 1981.

Every Latent Print Examiner who has been working more than a few years in any laboratory has similar “war stories” to tell. I have been fortunate in my three-decade plus career so far to work with some of the best Latent Print Examiners in the world. In 1982, I worked with Latent Print Examiners from the Illinois State Crime Laboratory and the FBI Laboratory to conduct laser examinations on evidence from the Tylenol cyanide murders. That case was the product tampering crime that caused the pharmaceutical industry to begin using tamper resistant seals on medications. One interesting fact not before reported (to my knowledge) was that Latent Print Examiners Mike Murphy (IL State Crime Lab), Jim Ridgely (FBI Lab) and I discovered that the cyanide partially dissolved the red dye on the inside of the Tylenol capsules in such a way that made the cyanide-tainted capsules glow like they were on fire during laser exams. Because the thousands of other (non-cyanide tainted) capsules we examined did not luminesce at all, it made life simple insofar as screening the evidence for which capsules were most important.

Later in the 1980s, in California, as a Forensic Scientist employed by the world’s largest (at the time) laser company. I gave training throughout the US (and in some foreign countries) on the use of lasers to detect latent prints. I also examined evidence for Latent Print Examiners from many crime laboratories that did not yet have laser or alternate light source equipment. One of the more notable cases I worked on involved evidence from the Night Stalker serial murders in northern and southern California (14 murders in 1984 and 85).

No Latent Print Examiners work alone - they are always part of a team. All latent print identifications are verified by a second, qualified Latent Print Examiner before the examination process produces an identification. Through cooperation and information exchange fostered by organizations like the International Association for Identification, The Fingerprint Society and SWGFAST (and some interesting web sites), Latent Print Examiners are able to leverage modern technology faster and more effectively than ever before. It remains a valuable crime-fighting tool worldwide, and the men and women working as Latent Print Examiners serve society in an indispensable role.

--Ed German