I found this on their website
I. Policy
As set forth in the policy, Housing Requirement for Freshman and Sophomore Students, the university requires all freshmen and sophomore undergraduate students to live in campus housing. As is the case on most residential campuses, on-campus housing for junior and senior students is not automatically guaranteed. During the spring semester, a lottery is conducted where interested junior and senior students may select housing from available rooms for the next academic year. The Office of housing Services also offers guidance and support to upperclassmen seeking off-campus residence.
-- when i visited Catholic they were building new dorms. They said that hopefully that would allow more juniors and seniors to live on campus. I also think they said that if you were in the honors program than housing was guaranteed for all four years.
the dorms that i visited were pretty nice, but they looked like they were relatively new ones
I'm not so sure about the saftey of the neighborhood surrounding Catholic and what type of housing options there are off campus.
But I would definitely check out Catholic University's housing website:
CUA Housing Services
it has links on the left so you can look at the off campus housing etc...
Hope this helps!