My oldest daughter graduated from college last year. They had good security, vehicle and foot patrol and stations where a student could hit a beacon type light that would also call police.
The kids generally traveled in pairs. They did have a few on campus problems but most of them were late at night and on the edge of the campus.
My daughter never had any problems.
As an anxious Mom. ~grin~
I'm glad to hear she didn't have problems.
I've specifically asked about just this scenario when students are studying into the wee hours at the library.
Once the doors are about to be locked for the night, most of the Universities have ID card swipe entry to ensure that only students remain in the library.