Not many students at Carleton feel that safety and security is an issue. Northfield is a small, family-oriented town and there's a very low crime rate. The campus is safe and well-lit. The biggest problem is bike theft, usually by people too lazy to walk from one class. If you lock your bike, you're safe. But if you leave it unlocked, just remember that the thieves don't discriminate about the bikes they steal. Your rusty clunker is just as likely get nabbed as the $2,000 jet propelled racing bike that you parked next to.
Laptops have been stolen from rooms, but it's pretty much the consensus that these thieves are not Carleton students. Northfield residents, namely high schoolers, have been known to come on campus and go into unlocked rooms. If you have something valuable in your room, it's just common sense to lock your door. Campus security is largely absent from Carleton life unless they're breaking up parties or giving parking tickets. But for the large part, that's all there is for them to do. They'll happily give you a ride across campus if you ask for it, but they wash their hands of stolen bikes, telling students to take theft reports to the Northfield police.