Breezeway Apartment Security Concerns

Hello! I hope it’s okay to ask this here, so please delete if not:

I recently received a notification from the police that a unit across from mine, down the breezeway, was being used as a flop house. Although the individuals have supposedly been removed and the original (albeit problematic) occupants are back, I no longer feel safe in my apartment.

I’m considering installing a camera and would appreciate any recommendations. Additionally, are there any effective protections, like a deadbolt for the outside, that I can use to secure my apartment when I’m not home? Any relevant advice would be greatly appreciated—thank you in advance!