The shooting of four people by a sniper in northwest Washington, D.C., on Friday afternoon forced residents and students into a lock down that lasted well into the night — until the gunman was found dead in his apartment.

"The suspect that we believe is responsible for this is now deceased,” Metropolitan Police Chief Robert Contee said at a nighttime news conference with Mayor Muriel Bowser. "We believe that the suspect took his own life as MPD members were entering or breaking the apartment where the suspect was located.”

The gunman opened fire on people walking in the warm April sunshine five floors below.