Certain crimes take their toll on even the most experienced police officers. Relive the toughest cases crime investigators ever faced. Front-line officers, senior investigators, forensic officers, detectives, family liaison officers, and arresting officers provide firsthand insight into what made each step of the investigation so difficult, and why, in some cases, they took years to solve.

Certain crimes take their toll on even the most experienced police officers. Relive the toughest cases crime investigators ever faced. Front-line officers, senior investigators, forensic officers, detectives, family liaison officers, and arresting officers provide firsthand insight into what made each step of the investigation so difficult, and why, in some cases, they took years to solve.