The Las Vegas gunman who carried out the deadliest mass shooting in recent US history also had scouted possible locations in Chicago and Boston, US media reported Thursday.Stephen Paddock had booked two rooms at Chicago's Blackstone hotel overlooking an expansive downtown park where the popular Lollapalooza music festival took place over four days in August, according to the website TMZ and NBC News.The 64-year-old gambler and retired accountant had also researched the city of Boston, NBC News reported, citing senior law enforcement officials who have been examining the gunman's electronic records.He never showed up for his Chicago booking, according to the media reports, but the August 2-5 timing may have offered Paddock an opportunity similar to the Las Vegas Strip concert Sunday night.Hundreds of thousands attended the music festival at Chicago's Grant Park, including Malia Obama, the former president's daughter.In Las Vegas, Paddock rained bullets from a nearby hotel tower into crowds attending an outdoor country music festival, killing 58 and injuring hundreds more.Investigators have said the attack, the deadliest mass shooting in recent US history, was meticulously planned."We are aware of the media reports and have been in communication with our federal partners," Chicago police spokesman Anthony Guglielmi said in a statement.The hotel management company and Lollapalooza did not immediately respond to requests for comment.The Blackstone is a historic luxury hotel where heads of state including former president Jimmy Carter, and artists such as Nat King Cole and Rudolph Valentino have stayed.