hey, why not try setting up a camera in your room instead of leaving your laptop on 24 hrs round the clock.
For ur situation, i think a network cam will do just fine. You can remote control the camera, take snapshots and record video with sound.
I have one fixed towards the front door. With downloaded app on my cell, I can visit the cam on my smartphone or view through the internet.
It has a two-way audio function. So I guess when u catch them, u can shout out loud "hey im watching u!"
Pretty good stuff from what i see.