The local sheriff has disclosed that an armed officer assigned to the Florida school where a gunman killed 17 people last week stood outside the building during the shooting and did not intervene.
Deputy Scot Peterson has resigned after being suspended, Broward County Sheriff Scott Israel said.
"I am devastated. Sick to my stomach. He never went in," Sheriff Israel said.
Sheriff Israel said Mr Peterson, 54, was the school resource officer of the Marjory Stoneman Douglas High School, and was at the site, armed and in uniform, when the shooting took place.
He said video footage showed Mr Peterson arriving at the building where the shooting broke out about 90 seconds after the first shots were fired, and that he remained outside for about four minutes. The attack lasted six minutes, Sheriff Israel said.
Asked what Mr Peterson should have done, Sheriff Israel said: "Went in, addressed the killer, killed the killer."
Mr Peterson is yet to publicly comment on what happened. Officers are reportedly guarding his home.
Sheriff Israel said Mr Peterson had not given a reason for why he did not go into the building where the shooter was. It is unclear if he will face charges.
