Air Force One departs Las Vegas past the broken windows on the Mandalay Bay hotel, where shooter Stephen Paddock conducted his mass shooting. Both rooms were scheduled for an August 6 checkout, the final day of the festival.

The report states Stephen Paddock had booked two rooms at the Blackstone Hotel on Michigan Avenue, one for August 1 - two days before the annual music festival began - and another for August 3, which was opening day.

NBC News reported that Paddock researched hotels around Fenway Park, according to an anonymous law enforcement official. The outdoor music festival held in downtown Las Vegas in late September featured Chance the Rapper, a Chicago native, and Lorde, among other artists. Among the attendees at the festival was former President Obama's daughter, Malia.

"We are aware of the media reports and have been in communication with our federal partners".

It was through his gambling that Paddock reportedly met his girlfriend Marilou Danley, when she was working as a hostess at a casino in Reno, Nevada, several years ago.

"What we know is that Stephen Paddock is a man who spent decades acquiring weapons and ammo and living a secret life, much of which will never be fully understood", Clark County Sheriff Joseph Lombardo said on Wednesday night.

Baker adds that officials from The Boston Regional Intelligence Center are "fully plugged in" to the investigation and in constant contact with Las Vegas authorities.

Investigators say they now do not have information which links Paddock to more assailants.

Danley, who was in the Philippines when the shooting occurred, flew back to the United States and is cooperating with authorities.

Meanwhile, Paddock's girlfriend Marilou Danley has arrived back in the U.S. for questioning - releasing a statement in which she has claimed that she was "sent away" to the Philippines by Paddock to prevent her from thwarting his plans.

The reserved hotel rooms overlooked the festival's main stage, entrance, and exit - not vastly different than the positioning of the Mandalay Bay suite he eventually used to attack innocent Route 91 festival goers.

Paddock opened fire on a music festival in Vegas on Sunday night, killing almost 60 people and wounding hundreds more. He killed himself as police were preparing to enter his room.

He even rented an apartment in a Las Vegas high-rise over another music festival the weekend before the massacre, possibly as a dry run. "That's also true of the Chicago police". Law renforcement sources said escaping a shooting would have been very hard because of the park's proximity to the river.

Officers found the suspect down on the ground, Lombardo said.