I'll get on my soapbox a bit on this one.
If we can be super anal (correctly) about finger-off-trigger, point in a safe direction, they're always loaded, etc, why can't we be the same about safe storage?
Just because "Won't someone think of the children?!" is the battle-cry of the anti-gunners doesn't mean that someone getting to your guns isn't one of the worst things that can happen.
I think that you should absolutely not trust your roommate, no matter who he is. Here's why. I have some dumbass friends. And so does your roommate. You don't know them and you don't know when they might be over. You don't know the handyman they might have at your apartment. He might be the kind of scuzzy guy who likes to snoop a bit.
It's real easy to say things like you shouldn't be friends or room with someone, "they know they'll have to deal with me", etc, but give me a break. This is the real world. Sometimes we have to live with people we don't really want to.
It's so, so easy to lock your stuff up. You can't afford a safe? What the hell is that? Be an adult. If you're strapped for cash, save up, ask for one for a holiday or birthday gift, check out eBay, etc, etc. Don't make excuses because something's a bit of a drag. That's like me saying I carry concealed but can't really afford to go to the range to practice.
Here's my setup. I have a shotgun and a pistol. My pistol lives in a $50 ADG safe which is one-way-bolted to my metal bedframe. I currently don't have a long gun safe, but I'm saving for one. Dick's is selling a Stack-On ten-gun safe for $80. I couldn't afford that the last paycheck, but I'll be getting it this one. Right now the shotgun is under the bed, unloaded, with the cable lock my pistol came with through the action.
Once I get the Stack-On, that'll get bolted to the closet wall/floor and the shotgun will go in there loaded and ready to go. When I come home, the pistol safe gets opened (five number combination) and when I get up in the morning, it gets shut. Within easy reach at night, locked up during the day in a very easy, very non-intrusive routine.
I'm not saying I've never left guns where I shouldn't have. And I know, I know, a determined thief can still get to them. But the average thief can't, and the average person can't and I know I won't ever have one of my own pointed at me when I come home early one day.
A lot of people say that it's not your fault if someone steals your gun and uses it. Maybe that's true. But I know how I'd feel if it happened, or if there was an accident. Never mind the law, it would kill me. I don't know how I'd get over that.
Enough preaching, I guess.
I'm just saying, let's be responsible and secure our weapons the same way we're responsible about handling them. It costs very little to take reasonable precautions. My setup allows for easy access and plenty of storage and costs (will cost) $130.