The episode "25 to Life" sees the BAU team encounter a man who's been given the prison sentence in the title — 25 years to life incarcerated — for murdering his wife and daughters. It's based on the real case of Jeffrey MacDonald, a former military doctor who was convicted of the 1970 murders of his pregnant wife and two daughters, though he's maintained that they were killed by intruders.
While the episode focuses on the team proving the fictional man's innocence, the real MacDonald remains in prison, with multiple appeals so far having failed.