Is the Offender Pulling a Knife?

Billy is 38 years old. He's probably much more physically capable than Niels who's 79. So could Billy have been the target in Niels and Daisy? They were witnesses that were eliminated based on victimology. That would be my first guess. But of course, I want to know, was anything stolen out of the cash register? Was there money taken? Was there a financial motive to this crime?"