A second source, a law enforcement official briefed on the case, said Paddock was doing online searches for large concert venues in the Boston area.
Boston's police commissioner says he will contact federal investigators about a report that the Las Vegas shooter researched locations in Boston.
NBC News reported that Paddock researched hotels around Fenway Park, according to an anonymous law enforcement official.
According to the NBC report, Boston police were aware of the reports and were working with federal officials. Numerous hotels researched by Paddock offered views that were heavily obstructed and Paddock eventually gave up on the search.
Gov. Charlie Baker said there is no evidence of an imminent threat that has anything to do with the Commonwealth, and deferred to authorities in Vegas.
Fenway Park gates for Game 3 of the ALDS between the Red Sox and Astros open at 12:38 p.m., exactly two hours before game time.
"We have a lot of work to do", FBI Deputy Director Andrew McCabe told reporters on Wednesday.
The Red Sox said in a statement that they have been told there's now no credible threat to Fenway Park.
Paddock's potential targets also included the most recent Lollapalooza festival in Chicago, which was held August 3 to August 6 in Grant Park, the officials said. Among the thousands of people who attended the festival was Malia Obama, daughter of former President Barack Obama.
Officials have said there is no credible threat to Boston.
Sunday's mass shooting was the deadliest in United States history, killing 59 people and injuring nearly 500 more.
Though it is unclear what his intentions with those actions, he ultimately chose to mount an attack from the Mandalay Bay Resort and Casino across the street from the Route 91 Harvest country music festival held last weekend.
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