What happened?

So we try to teach the kids right from wrong, and today Luke really pushed the limits. We ran into Albertston's to get milk and a couple other things and when we got out to the car, michael says "Luke stole a camera mom." I looked back and sure enough, he was proudly displaying a disposable camera he had stolen from the store. I had already gotten Brynley all buckled in her seat, but we got everyone out and marched Luke right back to the store. He had to take the camera and apologize to the lady at the checkstand. He was NOT very happy about this. I have caught him a coulple of other times trying to grab a piece of candy or gum when I've told him we weren't buying any. My friend's hubby is a cop, so maybe scare tactics will work... so far the little talks on why he can't take things (even though he wants them) aren't working.