It really depends on where you live. Theft shouldn't be an issue as long as you lock up and put valuables away. I highly recommend living in suburbs such as Lyons, Muirhead, Fannie Bay, Stuart Park, Bellamack, Durack etc. In my experience, I never found theft an issue in Howard Springs areas.
But areas like Moulden and Gray have high amounts of public housing and theft in the area. I would avoid living in Casuarina too due to the high amount of traffic flow in the area because of Casuarina Square.