I stopped bothering with a car alarm, no one here pays attention to them and every time they did break into the truck to steal tools or stereo equipment, I have usually ben far away. The last tiem they cleaned out the truck, in my underground, while I was on vacation (Europe). THey were nice enough to use a screw driver on the lock, bolt cutters on the padlocks in the back, and took everything of value out. They must have done several trips or over several evenings. Bastards very likely live in the complex as they must have know I was gone for a while.
There is no point in trying to catch them on tape or camera as that is apparently not enough for cops these days, so just shoot the pricks so they never forget you. Knee caps are good