Behind the Yellow Tape: On the Road With Some of America's Hardest Working Crime Scene Investigators (8 page)

On the Sunday afternoon that followed, after a horrible night’s sleep, Snow’s paranoia returned and began to get the best of him. It occurred to him that he might not have been wearing his gloves when he dumped Volpenhein’s body, and he decided to go back to the field to retrieve the tarps. But when he arrived, “I saw police everywhere,” Snow said, never once showing any remorse for anything except not being able to find those shell casings and stupidly forgetting to wear his gloves. Again he panicked, removing his tailgate and bed liner with a pair of pliers, tossing them into a Dumpster, and fleeing to his brother’s house in Tennessee (where he was not welcomed with open arms). He ultimately returned to Kentucky and nervously awaited his fate, while Boone County detectives began working the case.

“The academy taught us, if nothing else, to think outside the box,” Detective Brian Cochran told us as the three of us, along with Detective Tim Carnahan, took mountain curves at high speeds, en route to one of the hidden treasures of Boone County—a place called Rabbit Hash. Rabbit Hash is an odd little place with a population bordering on one or two, with a newly elected Labrador retriever as the town’s mayor. At least it was a close race. The pig that ran against the retriever was a formidable candidate, but his platform didn’t resonate quite as well with the populace as the retriever’s. Good ol’ Kentucky.

Detective Tim Carnahan was the second person from Boone County to go through the academy’s program. Before he came through the program in 2003, Tim was admittedly retirement bound, burned out, tired of working scenes just to see the cases get pleaded out. Our program infused new life into him and his work, which Linda Tally Smith and everyone else could see. After reaching Rabbit Hash, we stood looking out on the banks of the Ohio River, drinking peach soda pops and sarsaparillas, talking about the academy, the sheriff’s department, and the John T. Snow murder case. “We’ve got great support from our sheriff,” Detective Carnahan said. They really do have a lot of support from the whole county. The synergy in all of Boone County is incredible. A brand-new sheriff’s office with state-of-the-art facilities allows the CSIs to hone their craft when crime happens to take a night off. They are the best at taking what they have learned and making it better. That is particularly true of Detective Brian Cochran, whom Smith affectionately calls “Beaker” or “Bill Nye the Science Guy.” We like to call him “CSI MacGyver.” He can make a forensic tool out of just about anything. Cochran is part of the new, younger generation of CSIs, who really push the limits of the science behind crime scene investigation. If he needs a piece of equipment, he simply builds it rather than paying hundreds of dollars from a forensic supply store. We visited the lab with Brian and Tim and saw many items that were as well made as, probably better than, some of the fancy things for sale. Cochran is fortunate that his department lets him be creative and play with new ideas and new techniques. And it’s paid off for them.

The Rabbit Hash General Store in Boone County, Kentucky.
HALLCOX & WELCH, LLC

“Most of what we do isn’t written down somewhere,” Detective Carnahan went on to explain. “Sometimes the thing you do on a crime scene is the first time it’s been done.” That’s very true. Forensic science is much like law or medicine—it is a practicing art. Not only does the science change each year, but the environment CSIs deal with differs with every call. Each situation they face presents new and unique challenges. “How do you string a bloodstain in a trailer hallway, with that really nasty and greasy shag carpet that nothing will stick to?” Detective Carnahan said, referencing a recent case. “You simply must improvise.” And they do—in that case, by fashioning fishhooks from safety pins (which Detective Carnahan’s wife provided by running to the store) and hooking one end into the carpet and the other end to the colored string. In Boone County, working crime scenes can truly be a team effort.

This synergy and broad view of crime scene investigation is really what nailed John Snow to the murder of Patricia Volpenhein. Despite his paranoia, the evidence he left at the scene was limited: the two tarps, a glove, and tread wear from the truck. The glove and tread wear are typical of the kinds of evidence that can be photographed, cast, or collected. But the tarps, two eight-by-ten blue plastic tarps, presented a unique challenge. “Before the academy, I wouldn’t have processed the tarps,” Detective Carnahan told us as we got back into the vehicle to head back to the sheriff’s department. But now, he said, “Instead of looking at things as if we could not process them, we now look at everything as something that
can
be processed; that broad perspective is what your training provided to us.”

Television has provided viewers, and therefore potential jurors, with the unrealistic expectation that all CSIs are like the ones found in prime time. Unfortunately, that could not be any further from the truth. We have held classes on developing latent fingerprints in which thirty-year veterans in the field had no idea that a fingerprint could be lifted off anything other than something smooth, like a piece of glass. Imagine working crime scenes for thirty years without having the background to know how to develop prints off all types of surfaces? How many more crimes could have been solved?

Looking for a fingerprint on two eight-by-ten tarps (front and back) is like looking for a needle in a haystack. But the only way to find that needle
is
to look, and look is what Detective Carnahan did. He decided that in order to process the tarps, he needed to superglue-fume them. Common, everyday superglue, dabbed into a small pan and heated, causes the glue to give off gaseous vapors that stick to the ridges of an oily fingerprint and make it more readily visible. On larger items, a fan is sometimes used to help circulate the vapors throughout the container. In order to superglue-fume something, however, the item must be completely contained so that the entire surface area is exposed. Carnahan studied the situation and jotted down a schematic for a large frame that he wanted the maintenance guys at the sheriff’s department to create. The frame would allow the tarp to hang completely inside the container with both sides exposed. The real ingenuity came when, instead of building solid walls, he decided to contain the fumes with plastic wrap—industrial plastic wrap, like the kind used to wrap pallets for shipment on trucks. In essence, Carnahan made a large box using the plastic wrap for the sides. This made it easy to put the tarp and the superglue in the container, along with a fan to help circulate the fumes. It also allowed him to put a test print, his own, on the inside of the plastic to know that the process was working. With his superglue-fuming contraption in place, he simply wrapped the frame tightly and let the tarp fume. This procedure was performed twice, once on each tarp.

“I then simply cut the plastic and removed the tarp,” Detective Carnahan told us as we all walked down the corridor in the sheriff’s department to where all of the evidence is kept. The two tarps were still evidence at the time, but the case had just gone through all of its appeals, and the defense had failed. Snow’s fate was sealed. The sentence would stand for eternity, and the evidence could now be opened. “I then took the tarps and went over them inch by inch with a fingerprint loupe looking for ridge detail”—the fine lines of a fingerprint—Carnahan explained as he and Cochran located the tarps still sealed in large brown paper evidence bags. Detective Carnahan had gone over the tarps closely, front and back, using a Sharpie to circle areas that had at least
some
ridge detail. Then he hit those areas with a fluorescent dye stain to enhance the prints’ visibility so he could use a forensic light source to bring out more detail. And there it was—a nearly complete left thumbprint. “The guys who run AFIS [Automated Fingerprint Identification System—the searchable database of fingerprinted criminals] laughed when they heard I was trying to develop a print off a tarp,” Carnahan told us as we stood watching him and Cochran lay the tarp out on the floor of the police department garage, rehydrating the print by spraying it with the dye stain Ardrox so we could see it better. With the hum of the light source in the background, Carnahan and Cochran jumped around the tarp like elves, looking for just the right angle to view the print in detail. Though time and folding had changed the clarity somewhat, there the print was, right in front of us, about five feet up from a deep maroon-colored stain: the color of dried postmortem blood—Patricia Volpenhein’s blood. It was eerie to see the evidence up close and personal, and amazing that Carnahan had ever found the print in the first place.

Brian Cochran and Tim Carnahan examining the tarp for fingerprint evidence.
HALLCOX & WELCH, LLC

With the print developed, Carnahan needed a good picture to send to the guys at AFIS for comparison in the nationwide database, in order to see if there was a match. The first picture had a little bit of a wave from the tarp, which made it difficult for the guys to put into AFIS. But the next picture was perfect, and within hours a hit popped up on the screen—John T. Snow.

Latent fingerprint that was found on the tarp. The print
matched John Snow’s.
PHOTO BY TIM CARNAHAN, OFFICE OF THE COMMONWEALTH’S ATTORNEY,
54TH JUDICIAL CIRCUIT

Forgetting to wear his gloves was Snow’s first mistake—and leaving one behind would be his last. In order for a murder to be a capital offense in most states, meaning a death penalty case, there needs to be more than just murder for murder’s sake. It seems ridiculous, but there must be extenuating circumstances, such as multiple homicides, extraordinary violence, or rape. Premeditation alone won’t necessarily do it (and in this instance, the knowledge of premeditation only came out of Snow’s interview
after
his plea). This gave Snow’s attorneys some hope that they might be able to mitigate Snow’s punishment and avoid the death penalty. But Carnahan wasn’t finished with the evidence. Almost as an afterthought, Carnahan processed the glove that had also been found at the scene. It was a cotton knit style of glove and, unlike a latex glove, one that would be impossible to retrieve prints from. However, given the ever-increasing sensitivity of DNA testing, Carnahan decided to send the glove to the lab to see if any epithelial cells could be recovered. Knowing it was a long shot, he also sent the rape kit that had been done on Volpenhein, just in case there was anything to compare the evidence to. And there was. John Snow’s skin cells were found not only on the interior of the gloves but also on Volpenhein. With that evidence, the case became a capital murder trial because it appeared now that John Snow might have raped Patricia Volpenhein. When confronted with that evidence, Snow went crazy, showing the only emotion he ever displayed over Volpenhein throughout the whole ordeal. It wasn’t that he cared that he’d killed her (according to him, she was an old drug whore who deserved it); it was that he didn’t want to be “falsely” accused of doing something that he claimed he didn’t. He was adamant that he didn’t rape Volpenhein and that their sex was consensual. But to a jury, it would appear that rape was at least a possibility, and therefore the case would become capital in nature. Plus other evidence was mounting up against him as well. The tire impressions taken from the field were of an odd pattern, with three of the four tires having the same style tread, but with a different tread on the fourth tire, more of a snow tread. Just like the tires on John Snow’s truck. Furthermore, as the detectives in the case continued to work, they discovered video evidence of John Snow buying two blue plastic tarps at an AutoZone store. They also obtained video surveillance footage from the dump site that showed Snow’s red truck, missing taillight and all, driving around the facility as it was getting dark, on the night that Volpenhein’s body was dumped. All pretty convincing evidence—absolutely none of which would have ever been created if it hadn’t been for Snow’s paranoia about those shell casings with his fingerprints on them (which, incidentally, have
never
been found). No tarps would have been purchased and no fingerprints would have been left—nothing. Yet everything he did to cover up his guilt simply dug his grave a little deeper. Sometimes the CSI Effect does have its advantages; using what he learned from television actually caused Snow’s downfall.