Forever Knight (1992)

S3E3 Outside the Lines

A gruesome murder disrupts an undercover officer's mission. Detective Bruce Spencer is convinced he knows the killer, but without solid evidence, Nick grows wary. The situation is further complicated by Bruce's long-standing history with Tracy, who sees him as infallible. However, after Nick observes Bruce's violent actions, he realizes that things are far from straightforward. He must track down the real murderer before another crime unfolds.