" But the Orange County Crime Lab had recently integrated a new technique, PCR-STR (polymerase chain reaction with short tandem repeat analysis), which was much faster than RFLP and is the backbone of forensic testing today. The difference between RFLP and PCR-STR is like copying down numbers in longhand versus using a high-speed Xerox machine. PCR-STR worked particularly well for cold cases, in which DNA samples might be minuscule or degraded by time. "

― Michelle McNamara , I'll Be Gone in the Dark: One Woman's Obsessive Search for the Golden State Killer