The man accused of shooting at Secret Service agents on the National Mall in Washington expressed hostility toward the White House after he was wounded and taken into custody, authorities said Tuesday, as prosecutors prepared federal charges against him.

Jeanine Pirro, the U.S. attorney for D.C., said in an interview with ABC News that the man would be charged with an assault on a federal officer and discharging a firearm during a crime of violence. Asked whether she had any sense of why the gunman was in Washington or whether his actions appeared politically motivated, Ms. Pirro said he told authorities on the way to the hospital: “F the White House and ‘kill me, kill me, kill me’ three times,” she said.

Ms. Pirro confirmed the gunman was Michael Marx, 45, of Texas.

Shots rang out just south of the White House on Monday afternoon in an exchange of gunfire that also grazed a young bystander in an area packed with pedestrians, officials said.

The suspect, who was shot by Secret Service agents, was taken to a hospital with multiple gunshot wounds. Mr. Marx has yet to face charges. No law enforcement officials were injured, and there was no immediate sign that the man was targeting anyone in the executive complex, according to Chris McDonald, a congressional affairs official with the Secret Service.

The episode began about 3:30 p.m. near the intersection of 15th Street Southwest and Independence Avenue, when agents walked up to a man “who appeared to be carrying a weapon,” Mr. McDonald wrote in an email to Congress on Monday.

Matt Quinn, the deputy director of the Secret Service, told reporters that as the agents approached, Mr. Marx ran off and shot at them. The agents fired back and apprehended him, Mr. Quinn said. Shortly before the commotion rang out, Vice President JD Vance passed the scene of the shooting in his motorcade, but there was no clear indication that the suspect was targeting the vice president, Mr. Quinn added.

A firearm was recovered at the scene, and a 15-year-old boy hit by gunfire was treated for a non-life-threatening wound, officials said.

The shooting took place a little more than a week after a gunman stormed a security checkpoint at the White House Correspondents’ Association dinner and shot a Secret Service agent in an attack that officials said was targeted at administration officials.