While investigators uncover a twist in one murder case, digital evidence raises questions in another.

CCTV and GPS find the killer of Jasmine Pace; digital forensics reveals Megan Newton's killer.

Cameras capture a calculated poisoning plot; a routine stop uncovers another killer.

A 9-1-1 call captures the final moments of Collin Turner; CCTV helps reveal Mary Kay Wohlfarth's killer.

Surveillance footage plays a central role in tracking down the killers in two murder cases.

Footprints unravel lies in one case; CCTV retraces the final moments of a victim.

Footprints unravel lies in one case; CCTV retraces the final moments of a victim.

A killer records himself tampering with the weapon; phone data exposes betrayal.

Two separate cases reveal how betrayal leads to tragic consequences.

A double murder case ends in a confession; CCTV exposes a jealous former partner.