Beyond CSI: How big data is reshaping the world of forensics
Tune in to the average TV cop show and you’re likely to think crime scene forensics is a solved problem. Fingerprints, bullets, and fragments of broken glass can be unambiguously traced back to the source, then used by clever investigators to prove who committed a crime beyond a reasonable doubt.
And indeed, according to a landmark 2009 National Academic of Sciences report on forensic science, such techniques have done a great deal to help capture criminals and ensure innocent people go free. “Over the last two decades, advances in some forensic science disciplines, especially the use of DNA technology, have demonstrated that the forensic sciences have great additional potential to help law enforcement identify criminals,” according to the report. “Many crimes that may have gone unsolved are now being solved because the forensic sciences are helping to identify the perpetrators.” Yet not all forensic disciplines are created equal, according to the committee of scientific and legal experts that produced the report. Some techniques suffered from “a notable dearth of peer-reviewed, published studies,” the report found, many hadn’t been thoroughly tested to understand the likelihood that two samples of evidence could be falsely found to match, and the justice system relied heavily on the opinions of individual experts, not all of whom have the same level of training or accuracy. According to Fast Company, like other fields from medicine to advertising that are increasingly incorporating statistical analysis and big digital data sets, the forensics world has increasingly begun to consider how to balance human skill with automated analysis. And with humans not likely to leave the field anytime soon, crime labs have instituted statistical training for investigators and, in some cases, begun slipping test cases in with real-world evidence for technicians to analyze, looking to spot problems. Scientists have made progress in other areas of forensics as well, especially when it comes to fingerprints. While head of the latent print branch at the Army Criminal Investigation Laboratory, Henry Swofford worked on developing a software tool called FRStat for testing the strength of fingerprint evidence. The system doesn’t replace human analysts—instead, they use their usual methods for comparing two prints and document the areas where the two appear similar. Then, the software says how likely that similarity is assuming that the prints are from the same source, and how likely it would be if the prints came from two different people, based on existing databases of fingerprints. When Swofford left the Army lab in September, the software was in use in about 35 other labs around the country, and the Defense Department had tentative plans to open-source the tool, he says.