In the days and months before he mowed down concertgoers from his high-rise hotel suite, gunman Stephen Paddock rented rooms overlooking two other music festivals in Las Vegas and Chicago, authorities said.
They gave no details on what his intentions might have been.
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. He killed 58 people and injured nearly 500 before taking his own life.
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Authorities have been trying to track Paddock's movements in the days and weeks before the deadliest mass shooting in modern U.S. history.
In August, Paddock booked a room at Chicago's Blackstone Hotel that overlooked the park where the Lollapalooza music festival was held that weekend, a law enforcement official told The Associated Press Thursday.
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The official said no evidence has been found that Paddock ever came to Chicago that weekend. Lollapalooza draws hundreds of thousands of music fans every year to Grant Park.
The official was not authorized to discuss the case publicly and spoke on condition of anonymity after being briefed on the investigation. Paddock's booking of the hotel room was first reported by TMZ.
Also, the weekend before the Las Vegas bloodbath, Paddock had rented a high-rise condo in a Las Vegas building that overlooked the Life is Beautiful alternative music festival, Sheriff Joseph Lombardo said Tuesday.
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He offered no other details about what led Paddock there. The music festival featured Chance the Rapper, Muse, Lorde and Blink-182.
Investigators are looking to see if Paddock checked in or sought to book rooms in other hotels across the country near big concert events, CBS News justice and homeland security correspondent Jeff Pegues reports.
Paddock ramped up his gun purchases in 2016, but he was able to remain under the radar because of the type of purchases he was making and because he had no criminal history, Pegues reports.
This story originally appeared on CBSNews.com