To catch a killer
Last summer, the Los Angeles Police Department (LAPD) brought in a young African-American man on a felony weapons charge. After obtaining a DNA sample, the police found a close match in their database: previous samples taken from crime scenes thought to involve the “Grim Sleeper,” a serial killer linked to about 30 attacks and deaths in the Los Angeles area since 1985. The DNA from the young man wasn’t enough of a match to make him the Grim Sleeper. But the strains were so similar that investigators suspected the murderer to be someone related to him. In fact, the young man turned out to be the killer’s son. After a careful sting operation, 25 years after his first murder, the LAPD caught the Grim Sleeper. This triumph of modern forensic science is an offshoot of the rising field of genomics, the policy implications of which are of growing interest to Jennifer Hochschild, the...