Law & Order: Criminal Intent Episode 2.15 Monster

Detectives Goren and Eames investigate the case of a woman, Laura Dietrich, found slain in her apartment.

Goren and Eames initially focus their investigation on the victim's son, Mark Dietrich, recently paroled after serving 15 years for strangulation murder. But the detectives expand the investigation beyond the scope of the initial case when possible evidence for another case emerges. They meet the lead detective, Officer Ted Marston, who had investigated an earlier case of a raped park jogger, which had similar details present in their Dietrich case. They begin to believe the two cases could be linked.

After further investigation, not only does Goren suspect Officer Marston might have coerced false confessions from teenagers who subsequently were incarcerated for raping the park jogger, but Goren also suspects a sophisticated cover-up by Officer Marston to rush other cases to closure. Goren and Eames pit Officer Marston and Mark Dietrich against each other to expose the crimes of both. The lead detective is exposed about the coerced false confessions. The lead detective is also found to have raped/murdered the paroled's mother in order to halt her investigation of the park jogger case (She had become suspicious of her paroled son's talk and noticed connections to the park jogger rape) which might have caused that case to be reopened and the coerced false confessions to be exposed. Ultimately the mother's suspicions were confirmed; her paroled son is also exposed to have committed that other crime -- he was the actual rapist of the park jogger.