When you move into a new home have the locks re-keyed or changed. A locksmith can do this or, if you are handy with tools, you can change the lock yourself. Know who has every key to your home. Do not give keys to maintenance or delivery people. Do not hide your key outside.
Burglars know all the hiding places.
Be sure you deal with a reputable firm that provides approved systems. Check with the Better Business Bureau. Burglar alarms in Fullerton require a permit and annual renewal. For further information, contact the Police Community Services Bureau and speak to the Alarm Coordinator at 738-3103.