Gunman shot dead by Secret Service agents near White House: What we know

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 condition...