As CrimeOnline previously reported, Paddock made reservations at Chicago's Blackstone Hotel for the weekend of the Lalapalooza music festival, and specifically requested the two rooms he reserved to have views of the main stage.
-Hundreds of thousands attended the music festival at Chicago's Grant Park, including Malia Obama, the former president's daughter.
Paddock opened fire on a music festival in Vegas on Sunday night, killing almost 60 people and wounding hundreds more.
The gunman, who slaughtered 58 people and injured 489, had allegedly booked two hotelrooms overlooking the festival area where 400,000 people gathered over four days in the beginning of August.
According to some reports, the shooter had a similar view over the event crowd to the one he had in Las Vegas. With attendances reaching almost 100,000 people every day, Life Is Beautiful was home to artists such as Chance The Rapper, Kaskade, Lorde, and Pretty Lights. Running to either the west or east would have meant crossing two of Chicago's busiest roads, Michigan Avenue or Lake Shore Drive.More news: Taking a look at Thursday's four Game 1 starting pitchers
According to the NBC report, Boston police were aware of the reports and were working with federal officials.
The concert, which ran from September 22 to 24, featured Chance the Rapper, Lorde and Blink 182.
The gunman's girlfriend has also said she had no idea what he was plotting.
"I anticipate he was looking for anybody coming to take him into custody", Lombardo said.
Las Vegas Sheriff Joseph Lombardo said they aren't sure if Paddock was doing pre-surveillance and that investigators have recovered items and videos from the Ogden.