The Las Vegas shooter installed a camera in the peephole of his hotel room door — in addition to planting two cameras in the hallway, officials said Tuesday night.

Stephen Paddock had set up the devices around his Mandalay Bay hotel room so he could watch cops or security approach, Undersheriff Kevin McMahill said.

Paddock also had a total of 12 bump stocks in his room, which allowed his guns to mimic automatic weapons.

Using these weapons, it took Paddock nine to 11 minutes to carry out the worst mass shooting in US history.