The bookie's actions don't make sense
The bookie thought the roommates told the police about him, so he went straight over there to menace, threaten, and possibly murder them? If he really believed they had gone to the police, wouldn't he expect the police to be watching both the bookie himself and the apartment? So how stupid would this successful career criminal have to be to commit multiple crimes with the police watching and probably listening?
Of course he wouldn't behave like that. His first priorities would be to avoid incriminating himself and to get his fake story straight with Marcus. He could have Marcus watch the roommates to make sure they don't flee while they wait to see if the police show up at their door with what evidence they already could gather. If the police didn't question them, then they'd know the roommates hadn't gone to the police and they could resume making millions of dollars with the machine.