I wondered that, too, but it *is* the same apartment complex, so maybe someone else there told Norman cops they had seen Cheema go 'over there.' Barakat did say that Cheema went to that apartment all the time, so it's a regular occurrence.
I do feel sorry for Cheema, as being hard-of-hearing, cuz I can imagine how the officers yelled at him. *If* he's innocent, that had to be upsetting.
They also evidently knew what Cheema looked like, in order to to arrest him. Wonder if they got to the school records computer and got his picture out of there?