Thomas Matthew Crooks, the 20-year-old would-be assassin who opened fire on former President Donald Trump's Pennsylvania campaign rally Saturday, hid the weapon in advance, according to a Secret Service source.
It was not immediately clear where he hid it, however. By the time agents spotted him on the roof, he was already holding it.
"We went from golf range finder to AR-15, and now we have to fill in the gap," the source told Fox News.
TRUMP RALLY SHOOTING: LOCAL POLICE ‘BROKE...