CSI: Carolina

Bravo attends a forensic chemistry class

By Chris Horn

It's not that I'm squeamish, but I've never watched a complete episode of CSI, the popular TV crime scene investigation series that serves up a steady diet of homicides and chirpy details about maggots, hemorrhages, and other blood-and-guts trivia associated with murder and mayhem.

So why did I go to a forensic chemistry class where they teach students all about the real science behind crime scene investigation? Just curious, I guess. Plus, the instructor promised there wouldn't be any real blood!

When I arrive at the laboratory section of the class, Brad Richbourg is peering into a microscope, focusing the slide and describing out loud what he sees: a human hair with its fleshy root intact and minute dots of pigment along the shaft.

Richbourg knows a thing or two about crime. The criminal justice senior from Pelion, S.C., works undercover for a major retail chain, nabbing would-be shoplifters. Now he's learning the basics of what it might take to nab a murderer.

The lab instructor walks over to take a look.

“There it is—it's got tissue on the end, probably hurt when it was yanked out—you could do a full DNA profile on that,” the lab teacher says. “And remember: the more pigment dots, the darker the hair.”

Every week this past spring more than 100 students completed similar lab exercises in Forensic Chemistry 107. USC has offered advanced forensics chemistry for 10 years—in fact, long before CSI and other TV shows of that ilk became popular—but 107 is a new course intended for non-science majors. It appeals to criminal justice majors and anyone else intrigued with the details of crime scene analysis.

“A lot of CSI is not good science—it's entertaining but fictional. In this course the students learn from professionals who are actually doing forensics work every day,” said William Brewer, '91 Ph.D., an adjunct professor in USC's Department of Chemistry and Biochemistry who helped organize the course.

Demi Garvin, '87 Pharm.D., with the Richland County Sheriff's Department, is one of those professionals. She bemoans the fact that CSI is creating unrealistic expectations for jury members and hopes that USC's course will give students a more accurate depiction of what forensics analysis can do. From analyzing the shapes of carpet fibers to testing for gunpowder residue, Forensic Chemistry 107 is like an FBI lab primer.

William Martin, a marine science junior from Columbia, likes learning about the science behind crime scene investigation. “The instructors say so much of CSI is fakey, but the concept is correct. Technology can reveal lots of clues from a little evidence.”

In the lecture that follows the lab exercise on this particular evening, David Collins from the Richland County Sheriff's Department is discussing firearm and toolmark identification. He shows slides of the marks made by a knife and a screwdriver on an ATM door and describes the modified Griess test, which reveals the presence of nitrites from burning gunpowder.

The lecture hall is hushed as he recounts the case of a woman found in a retail business, shot dead at point blank range. The major evidence, .30 caliber bullet fragments, was confusing at first because the bullet pieces were so misshapen.

More ballistics tests revealed that the bullets had been shot in a different caliber rifle, which explained the odd markings. Based on that and other evidence, police questioned a nearby pawn shop employee who eventually confessed to the crime.

The highlight of the evening lecture comes when Gray Amick, '93 Ph.D., director of the DNA laboratory for the Richland County Sheriff's Department, fires a pistol loaded with blank ammunition. The lights are turned down, and students gasp as the .38 special roars and belches flame and smoke.

Amick's hands are wiped with a cloth that is chemically treated to reveal small, dark dots—evidence of gunpowder residue. “Gunpowder residue might also show up on the victim's palms,” Brewer tells the class. “It's not uncommon for a person to raise their arms defensively before they're shot at close range.” With that stark fact etched in their brains, students dismiss from the lecture, ready to tackle next week's lab exercise. Only some of them will become forensic chemistry analysts, but all are learning what every convicted criminal already knows: With good science, even the tiniest bit of evidence can sometimes solve a crime.