I had thought of this.
Who opened that door?
Either the killer opened that door, or an inside accomplice.
I don’t recall reading a description of the dude getting the cell call.Could have been the killer who then went to get his guns from his car.
As to an accomplice, could have been the room mate, or not.
Initially there was a report that police were looking for a mohammed. There was no follow up to that angle.
Initially, some stories said he kicked the door in. Right. Have any of those reporters ever tried kicking in a steel door in a steel frame?