Re: This is California. In July.
The deterrent value of an alarm is overstated. The thieves know a simple fact - the cops will almost always show up too late to catch them. My old house in south Atlanta was broken into at least four times after an obvious alarm was installed. In each case they got in, grabbed the TV and computers, and were gone before the police arrived. ONE time the cops arrived to see the criminal walking toward the street. He bolted through the back yard instead and got away clean.
On the good side, the alarm kept their visit short. Otherwise they could have taken their time since we were at work and gone for hours.