Except he DID kill again after they knew the first two murders were connected. 

This is my complaint: "police knew the bullets had been fired from a Colt Python — a relatively rare gun no longer on the market." I wish the public would've had a chance to know that detail. Maybe just maybe someone knew Ritchie had this particular firearm. That detail could've been enough to get someone to come forward. We'll never know. We are all extremely, extremely lucky he was in the wrong place at the wrong time otherwise we wouldn't even know any of this.