Snapped: Killer Couples (2013)

S18E4 Laura Martin and Robert Quinn

As Robert Quinn approaches his retirement, the discovery of a missing trucker's body in a secluded creek sends shockwaves through the department. With the investigation hitting a dead end, detectives stumble upon a seemingly insignificant detail that reignites their inquiries, unveiling a dangerous affair between two individuals entwined in a sinister scheme.