A man has been shot dead by United States Secret Service officers after opening fire on a security checkpoint near the White House, and a bystander has been wounded in the gunfire.

Several US media outlets have identified the gunman as Nasire Best, a 21-year-old man from the neighbouring state of Maryland who was known to the Secret Service and had a documented history of mental health conditions.

Shortly after 6pm (22:00 GMT) on Saturday, the suspect approached a Secret Service checkpoint at the intersection of 17th Street and Pennsylvania Avenue in Washington, DC, pulled a weapon from his bag and began shooting at officers posted there, the Secret Service said in a statement. The gunman was taken to hospital where he was pronounced dead. No Secret Service officers were wounded.

President Donald Trump was in the White House during the incident but “no protectees or operations were impacted,” the Secret Service said. The White House was immediately placed under lockdown.

Here’s what we know so far:

Who was the gunman?

US media say Best had tried to get close to the White House on several occasions last year.

The Reuters news agency said he had violated a “stay-away order” and had been identified as an emotionally disturbed person.

CNN reported that Best blocked an entry lane to the White House in June last year and was detained by the Secret Service. He claimed to be Jesus and said he wanted to be arrested. He was sent to the Psychiatric Institute of Washington for a mental evaluation.

According to CBS News, Best again tried to gain access to the White House in July and was arrested nearby by Secret Service agents. Once again, he was sent to a psychiatric ward.

Best had been living in Washington, DC, for about 18 months, CBS said.

CNN said social media accounts linked to Best included one post that appeared to threaten violence against Trump and another in which he wrote: “I’m actually the son of God.”

Where did the incident happen?

The intersection of 17th Street and Pennsylvania Avenue is on the northwest edge of the White House complex.

The main White House building is about 300 metres (980ft) away in a straight line. Walking there from the location of the shooting would take at least three minutes without taking into account all the security checkpoints along the way.

What has been Trump’s reaction?

In a post on his Truth Social network, Trump wrote: “Thank you to our great Secret Service and Law Enforcement for the swift and professional action taken this evening against a gunman near the White House, who had a violent history and possible obsession with our Country’s most cherished structure.”

Trump also referred to what his government has called an April assassination attempt and his White House ballroom project when he added: “The gunman is dead after an exchange of gunfire with Secret Service Agents near the White House gates. This event is one month removed from the White House Correspondents’ Dinner shooting, and goes to show how important it is, for all future Presidents, to get, what will be, the most safe and secure space of its kind ever built in Washington, D.C. The National Security of our Country demands it!”

What suspected assassination attempts has Trump faced?

While Trump was speaking at an outdoor campaign rally near Butler, Pennsylvania, on July 13, 2024, 20-year-old Thomas Crooks fired multiple shots from a nearby rooftop using an AR-15-style semiautomatic rifle.

Trump’s right ear was grazed by a bullet or shrapnel. One audience member, Corey Comperatore, was killed, and two others were critically injured before Secret Service snipers killed Crooks.

Authorities later described the shooting as an attempted assassination. The FBI said the gunman’s motive remained unclear.

In September 2024, Ryan Wesley Routh hid near the Trump International Golf Club in West Palm Beach, Florida, with a rifle while Trump was golfing. A Secret Service agent spotted him, and shots were fired before Routh fled. He was later arrested.

Prosecutors said Routh had planned the attack and had been monitoring Trump’s movements. He was convicted and sentenced to life in prison.

On April 25, shots were fired near the security screening area inside the Washington Hilton hotel while Trump, journalists, cabinet officials and guests were attending the annual White House correspondents dinner. Trump was evacuated along with other high-profile attendees.

The accused shooter, Cole Tomas Allen, was subdued by Secret Service agents and arrested. He has been charged with federal gun crimes and the attempted assassination of Trump.