Captain Stottlemeyer: Wallace Cassidy. He was on the jury when you were being sued six years ago.
Stewart Babcock: What are you talking about? Why would we care about somebody on a jury? That-
Adrian Monk: Maybe because you knew he was going to confess. Not for murder, for blackmail. Juror Number 12 was blackmailing you. He knew that you had murdered your first wife. After lan Agnew fell off your roof six years ago and sued you for negligence, the jury was brought here to visit the scene of the accident. One of them, Wallace Cassidy, wandered off. Most likely, he was looking for something to steal. Mr. Cassidy had a gambling problem. He was always in debt.
Sharona: I can't believe I went out with him. He's not even my type. I felt sorry for that stupid weasel.
Adrian Monk: Sharona?
Sharona: What!
Adrian Monk: We're working here. Mr. Cassidy never did find anything to steal. He found something a lot more valuable. It was the first Mrs. Babcock. He didn't leave without taking a picture and one of her fingers.
Captain Stottlemeyer: We have that picture, and we have the finger. It won't be hard to prove who it belongs to.
Adrian Monk: He sent you an anonymous note demanding money. You knew it was from one of the jurors, but you didn't know which one. At the time you didn't really care. Cassidy was small-time, and he wasn't asking for much. So you paid him and you thought that was the end of it. But it didn't end there. Cassidy kept coming back for more. So you decided to kill the blackmailer. But since you didn't know which of the 12 jurors it was, they all had to go, one at a time.
Sharona: Bastard! Not you.
Adrian Monk: Sharona, murderers, okay?