In 1982, in the town of Olathe, Kansas, a young banker named David Harmon was bludgeoned to death in his bed. His wife Melinda told authorities that two men intent on robbing the bank where David worked had broken into their home and committed the crime. Investigators believed, but could not prove, that Melinda was involved in a secret affair with family friend Mark Mangelsdorf, and that the two were involved in David’s murder. Nearly 20 years later, armed with new forensic technology, police zeroed in on the couple and was able to prosecute them.