[OldFriend]

Wondering if the man who keyed the locks for the home-owners had an extra key made for himself.

This is quite disturbing.

[jimboster]

You hit the nose right on the nostril. He has an accomplice in a local hardware store. People had extra keys made for their house/apt and were too lazy to wait around so they had them delivered. That's how they knew which key went with which address. That's why they're all from one one area of the city.