Two cameras in the hallway and one in the peephole allowed him to see if "law enforcement or security" were approaching, police said.

Officers are still trying to determine why Paddock, 64, opened fire on a concert from the Mandalay Bay Hotel.

However, they do know there was a high degree of planning.

The shooting - the worst in modern US history - has sparked debate over US gun laws, but President Donald Trump has said the discussion over what, if anything, needs to be done was "not for now".

(BBC News)