Paddock opened fire Sunday on a country music concert from a Las Vegas hotel room and killed 58 people.
According to the report, Paddock was aggressive and said that he need a room with a view because he would be celebrating his anniversary with his wife, and the two met at Lollapalooza.
The Boston Globe, quoting anonymous sources, said Paddock may have scouted Fenway Park and other Boston venues before settling on Vegas.
Lombardo said Paddock had 1,600 rounds of ammunition in his auto, along with fertilizer that can be used to make explosives and 50 pounds of Tannerite, an explosive substance.
The rent from the 111 apartments in the complex gave him more than $500,000 in net income after expenses in 2011, for example, a sales brochure prepared for potential buyers showed.
When Paddock checked into the Mandalay Bay on September 28, he requested an upper-floor room with a view of the Route 91 Harvest music festival, according to a person who has seen hotel records turned over to investigators and spoke on condition of anonymity.
McMahill said investigators had reviewed voluminous video from the casino and don't think Paddock had an accomplice in the shooting, but they want to know if anyone knew about his plot beforehand.
"They're going to be intermingled with the crowd".
The festival is popular with the children of the rich and famous - including former US President Barack Obama's eldest daughter Malia.
And see how you can help Vegas and the victims HERE! The official wasn't authorized to discuss the investigation and spoke only on condition of anonymity after being briefed on the investigation.
What officers have found is that Paddock planned his attack meticulously.
Paddock had 1,600 rounds of ammunition in his auto, along with fertilizer that can be used to make explosives and 50 pounds of Tannerite, a substance used in explosive rifle targets.
Monday: Investigators say they have located the suspect's girlfriend and say that she is overseas and is no longer a person of interest.
"We have been down each and every one of these paths", McMahill said.
County Clark Sheriff Joe Lombardo said he believed Paddock had an exit plan, but it was so elaborate he would have had to be a "superhero" to pull it off alone.