Most recently, Paddock looked into the most recent Lollapalooza, going as far as to book a room in a Chicago hotel called The Blackstone, according to The Chicago Tribune.
Stephen Paddock, the Las Vegas shooter, could've targeted a large swath of Lollapalooza had he checked in at a Michigan Avenue hotel this year during the music festival.
Each cross has the name of a victim killed during the mass shooting at the Route 91 Harvest country music festival this past Sunday.
TMZ reports its sources say Paddock had never booked a room at the hotel before, nor had his girlfriend and that neither showed up for the August booking.
United States media, citing multiple anonymous law enforcement sources, reported that searches of the Las Vegas gunman's communications and electronic equipment found that he had scouted locations in both Chicago and Boston.
The disclosures came as investigators struggled for a fourth day to explain what led the 64-year-old high-stakes gambler to open fire Sunday night on an open-air country music festival from the 32nd floor of the Mandalay Bay hotel casino.
The wealthy real estate investor opened fire Sunday from his multistory perch onto the crowd below, killing 58 people and injuring nearly 400.
This report comes as other information indicates that Paddock might have also booked rooms overlooking another major music festival in Vegas in September, Life Is Beautiful, which attracts about 50,000 people to downtown Vegas.
The person said Paddock was given the room for free because he was a good customer who wagered tens of thousands of dollars each time he visited the casino.
Danley, who was overseas for more than two weeks, said she was initially pleased when she was wired money from Paddock to buy a house for her family in the Philippines.
A former executive casino host at the Atlantis Casino Resort and Spa in Reno said Paddock had a "god complex" and expected quick service without regard to how busy the staff was at the time.
A federal official said authorities are looking into the possibility Paddock planned additional attacks, including a auto bombing.
Danley returned Tuesday from the Philippines, where Paddock had sent her before the attack, and was being interviewed by the Federal Bureau of Investigation.
NBC News reported that Paddock also researched Boston.
Police were reviewing video shot at the high-rise to check Paddock's movements.
Seven days before the assault, Paddock leased a room sitting above the three-day Life is lovely celebration in downtown Las Vegas. "That's the one in this one, and we are not there yet", FBI Deputy Director Andrew McCabe said.