Forensic Science: Integrating Evidence CSI-style
Volume X, Number 1, Spring 2010
Crime scene investigators on television make it all look quick and easy, and NC State faculty are doing their best to turn that bit of TV fiction into reality. Researchers in at least six of the University’s colleges are using their talents to crack unsolved crimes and make it easier for police, prosecutors, and evidence experts to analyze crime scenes. “Most of us aren’t forensic scientists,” says Dr. David Hinks, a professor of polymer and color chemistry in the College of Textiles (COT). “We’re scientists putting our expertise to work in a forensic setting.”
Dr. Ann Ross’ expertise, for example, involves revealing information from the bones of slain people. A forensic anthropologist in the College of Humanities and Social Sciences, she examines skeletal remains to determine who they might belong to and how the victims might have died. In one recent case, for example, she identified the remains of a murder victim found near Rocky Mount, North Carolina, by comparing the skull with an X-ray performed on the woman years ago.
With funding from the National Institute of Justice, Ross developed a software program that forensic scientists can use to determine the gender and ancestry of remains by plotting up to 33 locations on a skull and comparing the findings to characteristics of known populations. “You can also use the software in a situation where you have mass fatalities and have only bone fragments for comparison,” she says. Ross often is called in such situations, having identified bodies in mass graves left by “ethnic cleansing” in the former Yugoslavia and by the repressive regime of the late Chilean dictator Augusto Pinochet. She has devised mathematical equations for different groups that allow her to determine someone’s height by analyzing a leg or arm bone. “It’s hard dealing with death,” she says, “but what makes it easier for me is knowing that I’m helping provide closure for families.”
In the College of Agriculture and Life Sciences, entomology researcher Dr. Geoff Balme deals with bugs instead of bones. He studies the maggots and flies found at crime scenes. “We’re just getting started understanding some of the things insects do at these scenes,” says Balme, who gleefully admits never outgrowing his boyhood fascination with all things creepy and crawly.
After maggots feed on decaying flesh, Balme says, some species bury themselves in dirt while they pupate, and the resulting flies dig themselves out after emerging from the pupae. So he devised an experiment to determine how deep a grave could be without disrupting the process. He tosses beef liver scraps and maggots from two species of blowfly into the bottom of long plastic tubes and buries them with soil. After a few days, he removes cross-sections of the soil to see where pupae casings are located. Some flies have been able to dig out from as deep as 4 feet, he says. By noting the location of the casings and the soil temperature at a crime scene, Balme says, he can get a better fix on how long a body has been buried. “Without the science behind it, you’re just guessing,” he says. “That’s no good when you’re trying to nail someone for murder.”
Meanwhile, Hinks and COT colleague Dr. Keith Beck are after better science to analyze fiber evidence found at crime scenes. They are creating a database of dyes used in various fabrics so law enforcement can link with more certainty a fiber found on a victim to a fiber found in a suspect’s car, home, or clothing. “Trace fiber evidence is found at more crime scenes than DNA is,” Hinks says. “There’s a need for a more scientific basis in analyzing it.”
The textile researchers are developing a technique to snip off a tiny amount of fiber evidence to determine the concentrations of various dyes and other chemicals, then matching that evidence against their database. They are starting with automotive fabrics, using the extensive COT library of books detailing all fabrics in vehicles since the 1950s. The number of dyes used in vehicles is much smaller than those used in home furnishings or clothing. “What’s done today in forensic fiber analysis is relatively rudimentary,” Hinks says. “We want to make the testing more quantitative than qualitative and apply statistics to fiber evidence analysis.”
In the College of Management, Dr. Mitzi Montoya, Zelnak Professor of Marketing and Innovation Management, wants to make crime scene reconstruction and analysis more accessible to law enforcement. She leads an NC State team that recently won a $1.4 million National Science Foundation grant to develop a system to allow virtual recreation of a crime scene. “The best evidence experts don’t all work in the same city,” she says. “So we need to take advantage of electronic tools to bring them together where needed.”
Team members Dr. Michael Young, an associate computer science professor in the College of Engineering, and Tim Buie, an assistant professor in the College of Design, are using videogame technology to translate a 360-degree rendering of a crime scene captured with laser scanning and high-resolution digital photos into a scenario worthy of an Xbox 360 game. The location of evidence and angles of witnesses and suspects can be plotted precisely, and investigators—even jurors—can “walk through” the scene later to see if eyewitness testimony jibes with the physical evidence. “Crime scene investigation hasn’t evolved much in decades, despite advances in forensic science,” Montoya says. “NC State is speeding that evolution by introducing interactive, collaborative elements to take advantage of complementary expertise in high-tech fields.”