Why would the police and their city bosses want to keep this secret?
Because he was connected to them somehow.
The report indicates that he had friends in law enforcement that he would hang out with.
He was probably one of those "honorary cop" type people who suck up to the pigs and lick their boots, like how you're doing it here.
If Paddock had been Muslim, not only would we have known the motive, but we would have invaded a country because of it.