The last time anyone heard from Tracie Hawlett and J.B. Beasley, two teenagers on the verge of their senior year in high school, was on a sweltering July night in 1999. Tracie called her mother from a payphone to say they were on the way home from celebrating J.B.'s birthday — but the two never made it home. The girls' bodies were discovered in the trunk of J.B.'s car, less than a mile from the payphone, with gunshot wounds to their heads. Despite exhaustive efforts, including attempts to identify unknown male DNA found on one of the girls, the involvement of multiple agencies, national TV appeals, and even attempts at hypnosis of eyewitnesses, the case eventually went cold. In 2019, the use of genetic genealogy led to a breakthrough, resulting in a shocking arrest. Could they have finally found the killer?