JC,
Where abouts do you live? Having lived in Escondido some years back, I’ve got some experience with this crap, but it was with people breaking into my car, not casing my house. I ended up placing motion sensor lights with the power for the lights connected to a transformer to take the voltage down to, I think, 12V (your standard doorbell transformer) and had that connected to a doorbell in my room.
Caught two perps this way. It was relatively easy to set up, but I got a lot of false alarms from cats that would like the warm hood of the car. Both times I called the Police, they were extremely quick to respond and were able to catch the guys.
The easier thing obviously is just installing the motion sensor lights.
If you can observe the guy peeking into windows and get a good description, you’ll help the cops with their case against him should they catch him.
If you’re a female, I would definitely not stay there alone until the guy is caught. Best thing to do though is to call the cops immediately whenever this happens, you’d be surprised how fast they can respond.