So, the car alarms do not go off when a window is broken

They do, but they can be an annoyance. I got an aftermarket security system with shock sensors after my tires and rims were stolen in my driveway. Now it is just cut because I couldn’t make it stop in a restaurant parking lot once.

If I could go back I’d just get a fake blinking blue led and put it up in the corner of my windshield.

The after market systems all have some sort of led on them to let you know they are armed. It’s just a deterrent.

You can certainly get an after market system they work very well but I got tired of mine. It had its own remote that was clunky and separate from my factory remote. It would go off with big thunder or somebody driving past it with extreme bass. They make nicer ones that come with better remotes or take the place of your factory remote but they were expensive.

The place that installed mine, put a proximity sensor on a different car. It would give warning chirp if you got close to the car. Fancy stuff.

Edit: I think mine is a low end viper if you are looking for a place to start looking at them.

That is a thought, its a small church and this is the first time it has happened. At least outside security cameras.