When Austin York, Matt Self, Mark Barbosa, and Rosa Barbosa are found dead in a McKinney, TX home, detectives embark on a three year investigation. And just when it seems like the murders may never be solved, an eyewitness breaks the case wide open.

In Portsmouth, VA, a father comes home to find his 16-year-old daughter stabbed to death. With DNA and fingerprints police hope for an open and shut case. However, the case still goes unsolved for months until a piece of gum points to an unlikely suspect.

Ann Branson is found stabbed and beaten to death in her Kentucky home. There is little evidence at the crime scene and investigators struggle to find a motive. Ann's financial records provide the break authorities need to help catch the killer overseas.

In Owego, NY, Michele Harris disappears on September 11, 2001. Would she really leave behind her four children and run away from her soured marriage? When blood splatters are found in the home, police begin to suspect that Michele may have met a more sinister end.

Karin Strom is discovered strangled to death in her home. When a suspect emerges, investigators don't have enough evidence for a conviction. It will take twenty-six years to ultimately prove their case, and the final outcome surprises everyone.

23-year-old Stephanie Bennett is brutally raped and murdered in her suburban Raleigh apartment. Investigators work the case for years but their leads go nowhere. A closer look at a peeping tom provides police the break they desperately need.