A federal law enforcement source told PEOPLE Omar Mateen recently scouted Orlando's Disney World as a potential target before he attacked Pulse on Sunday morning, killing at least 50 people in what turned out to be the deadliest mass shooting in American history.
According to the source, Mateen and his wife Noor Zahi Salman visited Disney in April, but Salman told authorities more recently than that, Mateen was "scouting" Downtown Disney and Pulse specifically as targets. PEOPLE notes that unlike the other four Disney theme parks, Downtown Disney doesn't have metal detectors, a bag check, or security upon arrival.
In late 2015, all Disney World and Disneyland theme parks installed metal detectors at their entrances to enhance security. Disney also halted sales of all toy guns (including bubble guns) in each one of their parks.
Information about the massacre victims continues to emerge, but J.K. Rowling tweeted that one of them, 22-year-old Luis Vielma, worked the Harry Potter ride at Universal Studios, which is also in Orlando.
Police told the Orlando Sentinel there will be an increase in law enforcement at all Orlando theme parks and that deputies are being "extra cautious and vigilant in the park areas" since Sunday morning. Still, they expect theme park attendance to drop over the next few days.
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.