After a 1997 criminal case was largely decided by an unusual dark-and-light pattern in denim jeans captured by a security camera, a study of the case was used to set legal precedent for how patterns in photographs could be used as evidence. But now a study co-authored by postdoctoral information scholar Sophie Nightingale and information and electrical engineering and computer sciences professor Hany Farid, an expert on deepfake images, questions the reliability of such evidence. "Even under ideal conditions, trying to get an exact match is difficult," Professor Farid says. "This technique should be used with extreme caution, if at all." To conduct the study, they bought 100 pairs of jeans from local thrift stores, and they had 111 workers send in pictures of their own jeans. They then compared images of similar seams. According to the reporter: "The data showed that two images of the same seam often looked quite different -- so much so that it was often impossible to tell whether a pair of images were of the same seam or different ones. Much of the problem, the researchers concluded, comes down to the fact that cloth is flexible: it stretches, folds and drapes in complicated ways, which changes how it looks in photos. ... The lack of distinctiveness in images of seams significantly limits the accuracy of jeans identification, according to the study. The algorithm made a significant number of false matches between different pairs of jeans." Their study is available at PNAS.org.