Most door and window locks might keep out someone who just rattles the knob, but they won’t stop a determined burglar. Nationally, thieves enter homes through an unlocked entry in more than 40% of all residential burglaries.
Every exterior door should have a dead-bolt lock with a one-inch throw. If you have a key-in-the-knob lock, install an auxiliary lock like a bolt or a cylinder dead-bolt. When you move into a new house or apartment, re-key the locks because you never know who had keys.
Do not hide keys in mailboxes, planters or under doormats. Police suggest that you trade keys with a trusted neighbor instead.
Some additional security tips to consider:
Secure sliding glass doors with commercial locks, a wooden dowel in the track or insert a nail or pin through a hole drilled in the sliding frame that projects into the fixed frame. Lock double-hung windows with the proper sash lock or by sliding-bolt.
Consider grilles for street-level windows if you live in a high-crime area.
Locks are less effective when installed in flimsy or weak doors. Make sure outside doors are solid, at least 1-3/4 inch metal or solid wood.
Be sure doors fit tightly in the frames and hinges should be on the inside. Swing-out doors should have hinges with non-removable pins. Frames should be shimmed securely at the hinges and the strike-plate area. Also, be sure to secure the door between your house and garage since that is a common entry spot for thieves.
Install a peephole in all entry doors so you can see who is outside without opening the door. A short chain lock is not a good substitute because it can be broken easily.