Eb23, I would add two things to the above: 1) check with the University police -- I think every school in DC has them -- about which garages are safest or most frequently patrolled. Nowadays Univ Police Depts. have to keep logs and make public reports of crime on campus, some are even online to make it easy. That may help you choose which bike rack locations might be more secure. 2) Get to know the parking attendants who work in the garage you use. Always be polite to them, say Hi and all that so that they get to know you. A little kindness can get you a lot of extra security and that never hurts in the big city.