Sliding glass door have a wooden rod in the track so it can't be opened and pins in the overhead frame so it can't be lifted out?
Landlord or building manager tightly control all keys?
Check Out Your Building...
Is there some kind of control over who enters and leaves the building?
Are walkways, entrances, parking areas, elevators, hallways, stairs, laundry rooms and storage areas well-lighted 24 hours a day?
Are fire stairs locked from the stairwell side above the ground floor so that you can exit but no one can enter?
Are things well-maintained? Are burnt-out lights fixed promptly, shrubs trimmed, trash and snow removed?
Check Out Your Neighbors...
Get to know your neighbors. Join or organize an Apartment Watch Group so neighbors can look out and help each other.
If you live in a large building or complex, think about a tenant patrol that watches for crime around the building, provides escort services for the elderly and handicapped, and monitors comings and goings in the lobby.
Work with landlords to sponsor social events for tenants.
Look beyond problems to root causes. Does your building need a better playground, a social evening for teens, a tenant association, new landscaping? Work with the landlord for changes that will make everyone proud of where they live.