Attorney General Merrick Garland said Tuesday he was deeply alarmed after a shooter was able to get close enough to attempt to assassinate former President Donald Trump earlier this month.

Garland spoke to NBC News on Tuesday, describing the attack — which left one of Trump’s supporters dead at a rally in Pennsylvania — as a “security failure” that “should not happen in America.” The FBI said last week Trump was struck by a bullet in the ear, although officials are still searching for a clear motive in the attack.

“This is extremely alarming,” the attorney general told NBC. “Our democracy will not survive if people decide that the way in which they get the outcomes they want … is by killing someone.”

“That’s why we have to find out what happened here, why it happened and make sure it doesn’t happen again.”

Republicans have continued to react with fury following the shooting, prompting Secret Service Director Kimberly Cheatle to resign earlier this month amid a bipartisan push.

Garland went on to say there is no question that Trump was the target of an assassination attempt, calling the shooting “a heinous attack on democracy itself.”

“This was a major security failure,” he added. “This kind of a horrific attack on a former American president just can’t continue. We have to be sure we stop this.”

He added, however, that in a democracy people should be able to argue and disagree, loudly at times, and then vote to resolve those differences at the ballot box.

“There will always be a winner and a loser ... and that person’s supporters will always be upset,” Garland said. “But in a democracy, we have to accept the results. Otherwise, democracy won’t survive.”