gary parkison, but it isn't for a checkup. >> basically, i need you to help he needs to just go away.destroy my life. >> detective harn, of the concord, california, police department is posing as a hit man after his department learns from an acquaintance of parkison he is looking for a hired gun. >> basically, what do you want to know? you want to know why? >> yeah, i'd like to. >> well, this guy's been screwing me really, really bad and trying to get me arrested for a bunch of [ muted ] i didn't do. he's got a lot of money on it. >> what's this guy's relationship to you? >> he's an ex-lover. >> i could see his hand shaking and his voice was trembling a little bit when he was trying to light his cigarette, had problems. i thought he was going to burn up the interior of my car. it definitely put me at ease to see how nervous he was, and i felt more in control of the situation. >> detective harn is in control of the situation as parkison makes all the right, or should we say wrong, moves? >> basically i need to make sure it doesn't come off on to me. >> parkison has a plan. >> well -- a