Did you work at the bar? The first time, there's an event where Perry asks for a free drink -- If you tell him off, he'll follow you back, and Kira kills some of his goons.
After that event, the option to hunt Perry should show, but you need to talk to the Sheriff first (for the gun). After that, you'll need to work at the bar again, till a 'night' event with the looter chick. She basically tells you how to find him, and from there, it's picking who, if any, goes with you, and his fate. -- Personally, I'd kill him, because the other two choices aren't all that good; exiling allows him to continue doing what he does else where, while with arresting, you're basically feeding him for free, or allowing him to bide his time.
