Cold Case Files - Season 5 Episode 9 Something Snapped/A Killer's Dream

On a summer night in 1987 a mother worries and waits for her 19-year-old daughter to come home. But Diana never comes home and she's found raped and strangled near the Hudson River. Investigators suspect her friend, Michael because his alibi is shaky and witnesses place his truck near the crime scene. Trouble is, he passes a polygraph and his DNA is no match. Nevertheless, Michael remains the chief suspect for 17 years, until DNA fingers another man who offers a chilling story of Diana's last breath. Then, a young family's life is shattered when a San Antonio interior design shop becomes a crime scene. In 1983, a young mother is raped and murdered at work. The crime remains unsolved for two decades. Then in 2003 detectives reopen the case pegging their hopes on DNA. But when the evidence turns up missing, detectives worry this case could be over before it starts.