Castle, Season 2

Kate Beckett:
How does a prosecutor get into business with a criminal?

Rick Castle:
Well, it's hard out there for a pimp who's also a DA. Ooh, that be a good character for a novel. A star prosecutor who's always excelled at everything he's ever done. He couldn't possibly imagine that being a pimp would be a bigger job than he can handle by himself. But one day he gets a call, one of his girls has been knocked around by a client. He realises there's nothing he can do about it, he's a very public figure. So, a white collar prosecutor decides to hire a blue collared enforcer. Can't exactly take out an ad on Craigslist for that. But fortunately enough, he has a big stack of qualified candidates sitting right on his desk.

Kate Beckett:
Which is where he found John Knox. A criminal who mostly managed to stay out of prison.

Rick Castle:
Which makes him a smart criminal.

Kate Beckett:
Yeah.

Rick Castle:
Buckley offers him a deal. Come work for me, I'll throw your case. And Knox does. For a while, everyone's happy. But then Knox decides he's not happy being number two anymore. He takes Buckley's client list, tells Buckley to take a hike.

Kate Beckett:
Knowing that Buckley can't do anything about it without risking exposure.

Rick Castle:
But Buckley's never backed down from a fight in his life. He gets the cops to drag Knox down to his office to remind him who's boss.

Kate Beckett:
But Knox took it up a notch, sending a warning shot across Buckley's bow by threatening his brother-in-law.

Rick Castle:
And when Buckely wouldn't back down, Knox threw him off the roof of the parking garage.

Kate Beckett:
Jeez, if only we had some proof.

Rick Castle:
Who needs proof? What a great story.