Moore works with Seattle's Snohomish County Sheriff's Office and takes on her first-ever cold case as a genetic genealogist – the double homicide of Jay Cook and Tanya Van Cuylenborg. The young couple disappeared in 1987 after taking a ferry from Vancouver to Seattle and were later found miles apart, gagged, bound and brutally murdered. With a smattering of clues, but no real leads, the case was cold for 30 years. The episode includes interviews with Jay's parents, Gordon and Leona Cook; Tanya's brother, John Van Cuylenborg; Snohomish County law enforcement retired Sheriff Rick Bart and Detective Jim Scharf; and radio reporter Hanna Scott.

Police in Idaho Falls, Idaho, have spent the last 23 years trying to solve the case of 18-year-old Angie Dodge who was raped and murdered in her own apartment in 1996. They turn to investigative genetic genealogist CeCe Moore, but no genetic genealogist has ever solved a case using such degraded DNA. Despite the challenge, Moore is able to come up with the name of the potential killer. The episode follows the Idaho Police Department as they track the suspect, collect his DNA and match it to the DNA found at the crime scene. Cameras are rolling as police move in for a heart-pounding arrest. Moore's work on this case also helps exonerate Chris Tapp, who was wrongly accused of Dodge's murder and spent 20 years in prison. The episode features interviews with Angie's mother, Carol Dodge; Idaho Falls Police Department's Captain Bill Squires; Detective Jeff Pratt; and reporter Bryan Clark.