The granddaddy of all forensic tools, fingerprinting, dates back to around 200 B.C. in China. But in the 1930s, criminal investigators discovered latent prints could be left on fabrics, including the inside of gloves. The FBI’s Integrated Automated Fingerprint Identification System, a national register of fingerprints, was launched on July 28, 1999, and revolutionized crime fighting, becoming a most important tool—until the innovation that follows this one.