Meticulous planning by Las Vegas gunman before he opened fire

Twelve of the rifles Mr. Paddock had in his luxury suite on the 32nd floor of the Mandalay Bay Resort and Casino were outfitted with a "bump stock

Before he mowed down concertgoers from a perch high in a hotel tower, Stephen C. Paddock created a ring of surveillance around him, with video cameras in his suite and in the hallway, law enforcement officials said on Tuesday. But investigators were still at a loss to offer a motive for the massacre.

The cameras — apparently intended to warn of approaching threats — along with the 23 guns, hundreds of rounds of ammunition, and other equipment found in the gunman’s hotel suite, suggested a thought-out plan to have plenty of time to wreak carnage while holding the police at