Monday Briefing

After shots rang out, Donald Trump was swarmed by Secret Service agents.Credit…Doug Mills/The New York Times

‘Defiant in the face of wickedness’

Shots rang out at a Trump rally on Saturday night. The former president clutched his right ear, spurting blood, then ducked for cover as his supporters screamed and Secret Service agents leaped on top of him.

Within moments, someone shouted “shooter down,” and the agents began moving Trump offstage. He pumped his fist in the air and seemed to shout “Fight! Fight!” as the crowd erupted with chants of “U.S.A.!” See a visual timeline of the shooting.

For the first time in more than four decades, a man who was elected president of the U.S. was wounded in an assassination attempt. The shooting killed one man, injured Trump and critically wounded two others. Secret Service snipers killed the assailant. Here’s what to know.

F.B.I. agents are now investigating the shooting as a possible domestic terrorism attack and assassination attempt. The officials said that they had found no indication that the 20-year-old gunman, identified as Thomas Matthew Crooks from Bethel Park, Pa., was part of any larger plot, and that their top priority was determining his motive.

The officials said they had not uncovered evidence that the shooter, a registered Republican, had mental health issues. They said that his phone, rifle and a possible “rudimentary” explosive device found among his possessions had been sent to the bureau’s lab in Quantico, Va. The shooter’s family was cooperating with the investigation, the F.B.I. said.