Quote from Adrian Monk in Mr. Monk and the TV Star
Adrian Monk: Sharona. Sharona: What? Adrian Monk: Brad. He lied to that girl about her script. I was there. Sharona: So what? He was being polite. Adrian Monk: No. No, no, no, no. He was... He was wearing one of those pulse monitors. His heartbeat didn't change, not a fraction. He's a sociopath. That's how he beat the polygraph test. He did it. He's the guy. Sharona: He can't be the guy. Adrian Monk: He's the guy. He's the guy.