The Mentalist Season 3 Episode 21
Like A Redheaded Stepchild
-Walton Parcel, prison guard and wannabe detective is stabbed to death in the street. Walton was trying to get inmate Marcus Lansdale transferred to a high security prison.
-Rigsby's father, Steve was a former inmate at the prison. He first tells Rigsby he won't help a cop but then gives him a lead.
-Rigsby and Van Pelt take down Butch, a local meth dealer on Steve's information. Turns out Butch didn't kill Walton. Steve used Rigsby to take out his local competition.
-Jane observes the inmates at the prison. He leaks that inmate Nick snitched on Lansdale. When Lansdale goes to kill Nick, he's caught and will be transferred to a high security prison.
-Nick escapes through the laundry when he believes his life is in danger. It's the same escape route he used when he robbed jewelry stores. Walton saw him and Nick killed him.
-Rigsby tells Grace that he can't come to her wedding because he's still in love with her.