The only things we actually have hard evidence that he stole was weed. While plenty of other things have mysteriously gone missing while he was the only one home, I doubt any of it has enough basis for getting him arrested. Even then, my roommates are in the process of moving all the valuables out of the house and into their girlfriends' places.
Now, confronting him about it and him throwing punches at a cripple would certainly get that done, but goading him into beating the crap out of me is both entrapment and... less than fun. The funny thing is that I've got such a pain tolerance now that I'd probably laugh at him while he punched me. It's another reason I want to stand by my roommates for this one - if anyone's gonna have to take a punch to the face from this guy's instability, I'd much prefer it to be me than one of them. The probability that he's going to go violent from us giving him a deadline for paying everyone back or GTFO is pretty high.
I'd say your point about paying zero dollars is right, but he IS lackadaisically paying people back at extremely slow rates. He's been asking mommy and daddy for money, and they can't afford to keep paying his rent as is, hence the job hunt. If he could get away with them paying for his living, he absolutely would. Either way, he DOES eventually give people partial payments back, in an attempt to show them "look i'm trying" so he can go back to playing Madden for hundreds of hours instead of finding a job. Either way, his holding pattern has been maintaining the illusion of paying people back (interestingly enough, I'm the only one in the house he owes no money to outside of stolen wares. I've seen enough of his bullshit that he knows there's no way I'd be willing to lend him money) as an ever-present possibility. He's currently paying what he can "afford" out of the rent (even though he's eating out and smoking a pack of cigs a day) while repeating "don't worry dude, i'll have the money soon" for the past several months. If I leave, the illusion breaks, and then my roommates have to deal with him "swearing" he'll be able to cover my portion too, even though he's the one that kicked me out. In his perspective, he's barely scraping below the radar of not paying anyone, and soon enough the lease will be done and he'll take off without paying any of the utilities (although he's gonna pocket that sweet security deposit he never paid off).
Let me tell you another story about him to show you what happened the last time he moved out of somewhere (I guess I have to give him a name, so K will do for now): I had an apartment with another roommate, who left to home for the summer and the last 2 months of the lease. K didn't owe anyone money yet, and was being a good friend, so I offered to him potentially living with me, and sub-letting my apartment from the other roommate. He of course, was super down. K talked to my roommate, and even before he brought up the rent issue, K offered to pay the rent in full (~1200 bucks). Cool right? Anyways, the two months went by (I was still in the chair at the time), and he only showed moderate signs of being a dickhole (always calling it his apartment instead of ours, etc.) while still at least doing some chores and keeping clean. He sends my roommate the rent checks, which mysteriously bounced. He kept saying he didn't know what was going on, but pretty soon it came time to move again, and he had to throw down money for a deposit and first rent and all that. He had a job at the time, so things seemed fine. But then he suddenly didn't have the money for my roommate at all. K kept telling him "oh i'll get it don't worry" and throwing him 50 bucks at a time for a few weeks, but then one day he got blisteringly drunk at my (now former) roommate's new place during his birthday party, and shouted at him/drunk dialed him after he got kicked out for hours about how hilarious it was that he wasn't ever going to get his money back and how he'd lost. K appologized in the morning, but hasn't paid him a cent since, and it's been around 7 months.
It's getting close to move-out time, and the exact same thing is about to happen.