Hidden cameras may help you get a good I.D., but cameras in plain view may also act as a good deterrent and prevent you from even needing an I.D. If your house is concrete, you most likely need a wireless multi-channel system. I suggest wireless assuming you don’t have anywhere to hide wiring. If you do, though, a hardwired system may work better as I’m not sure how concrete may interfere with the camera’s communication. Definitely consult an expert first.
Good hiding places may include behind a plant, in a bookcase (perhaps disguised in some way) or something like that.
Or you can opt for a hidden camera that looks like something else like a smoke alarm, a wall clock or an ordinary ceiling light.
Do you already have an alarm system? Whichever camera you select should be able to integrate with your current system.
Home Security Store has some affordable DIY options for cameras, alarms and other devices, which may help:
Good luck to you. Having been burglarized before, I know how bad it sucks to feel vulnerable in your own home.