WASHINGTON — The U.S. Secret Service fatally shot a person who opened fire on officers at a security checkpoint on Saturday in an exchange of gunfire that briefly locked down the White House, officials said.

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The shooting happened shortly after 6 p.m. when a male approached the Secret Service checkpoint at 17th Street and Pennsylvania Avenue NW, pulled a gun from a bag and opened fire on officers, the Secret Service said in a statement.

The officers returned fire and shot the suspect, who was taken to a hospital, where he later died, the Secret Service said. The agency said the shooting remains under investigation.

A bystander was also shot, the Secret Service said, but it was unclear who fired the round that injured that person. Their condition was not immediately available.

Six senior law enforcement officials briefed on the matter identified the suspect as 21-year-old Nasire Best.

Best had a documented history with local law enforcement, and five senior law enforcement officials said he had a history of mental health concerns.

Best was placed under arrest on a charge of unlawful entry on July 10 after he walked into a restricted area near the White House, according to a court document filed in the Superior Court for the District of Columbia. During that incident, he claimed he was Jesus Christ and that he wanted to get arrested, the filing said.

He was known to the U.S. Secret Service for walking around the White House complex asking about how to gain access at various entry posts, the filing said.

In June, he was involuntary committed for obstructing vehicle entry to the White House complex, the document said.