Castle (2009)

Season 3: Episode 13

When the detective who investigated Beckett's mother's murder is shot before Beckett's eyes before he can give her new evidence in the case, Beckett's old wounds are reopened. The investigation of the detective's death leads the team to an old scheme which may provide the answer to why Beckett's mother was murdered and who ordered it. Beckett and Castle's relationship takes a new turn.