The man suspected of firing down into an outdoor music festival on the Las Vegas Strip on Sunday night, killing at least 59 people and injuring 527, managed to haul at least 23 firearms—plus ammunition, gun stands, scopes, and other accessories—into his hotel room on the 32nd floor of the Mandalay Bay.

The newest, deadliest mass shooting in modern U.S. history has already opened up a debate over questions of security in one of America’s most wide-open (and yet closely surveilled) cities. As the u…