Your DNA Test Could Crack a Cold Case

Consumer DNA databases are a powerful new tool for police

Illustration: Wenkai Mao

LLike most people who take a 23andMe test, Georgia resident Jessi Johnson Still was curious about her ancestry when she spit into a tube and mailed it away to get her DNA analyzed.

After getting her results back, she uploaded her DNA data to a website called GEDmatch that lets…