Florida shooting: Armed officer stood outside Parkland school building and did not intervene while 17 were killed

An armed officer stood outside the Florida high school where 17 pupils and staff were shot dead and did not go inside to confront the gunman, the county sheriff has said.

Deputy Scot Peterson, who was on duty at Marjory Stoneman Douglas High School on the day 17 people were shot dead, has resigned after an internal investigation discovered he failed to intervene in the shooting.

Broward County Sheriff Scott Israel said video footage showed Mr Peterson arriving at the Parkland school’s freshman building about 90 seconds after the first shots were fired on 14 February.

The deputy then lingered outside for at least four minutes as victims were gunned by a lone shooter wielding a semi-automatic AR-15-style assault rifle.

Details of his actions emerged hours after Donald Trump claimed letting some teachers carrying concealed weapons in the classroom would “solve the problem” of school shootings “instantly”.

The US President suggested that teachers who were trained to use guns would “immediately fire back if a savage sicko came to a school with bad intentions”.

Mr Israel said Mr Peterson had resigned after being suspended after video of his non-intervention in the slaughter emerged.

“I am devastated, sick to my stomach,” the Sheriff said. “There are no words. I mean these families lost their children. We lost coaches. I’ve been to the funerals.”

He added: “He was armed, in uniform… What I saw [on the video] was a deputy arrive at the west side of building 12, take up a position, and he never went in.”

Asked at a press conference what Mr Peterson should have done, the Sherriff replied: “Went in. Addressed the killer. Killed the killer.”

The deputy had been deployed to the school as a resource officer on the day of the shooting. He has not explained why he did not enter the freshman building, where most of the victims were shot in the second deadliest gun attack at a public school in US history.

He resigned after being suspended without pay and placed under investigation.

Mr Israel said he would not yet release the video and may never do so “depending on the prosecution and criminal case” against Nikolas Cruz, the 19-year-old former student who is charged with 17 counts of premeditated murder.

Authorities have said that Cruz, who was expelled from Stoneman Douglas High last year for unspecified disciplinary problems, made his getaway moments after the shooting by blending in with pupils fleeing the school for safety.

Mr Peterson is one of three members of the Broward County law enforcement team investigated following the massacre.

Two other officers have been put on administrative leave during an internal investigation determine if there they should have done more when notified previously about Cruz’s behaviour. Numerous reports about Cruz had been to the Sheriff’s department over the last 10 years.

It has also emerged officers arriving on the scene from the adjacent city of Coral Springs thought the gunman was still inside as they searched the building, based on a security camera video feed they mistakenly believed was showing them real-time images but was actually footage from 20 minutes earlier.

Coral Springs Police Chief Tony Pustizzi said the confusion stemmed from human error and a “communication failure,” not malfunctioning equipment. He insisted that the mishap did not put any lives in danger.

Mr Peterson's failure to confront the gunman appears to undermine President Trump's insistence that armed teachers would mean "attacks would end".

"An armed sheriff's deputy won't do it, but a kindergarten teacher who is already underpaid should be expected to be a weapons expert, and be stocking an A-15 in their classrooms to help NRA client gun sales. What could go wrong," said Amy Siskind, the president of the pro-women and girls group the New Agenda.

Mr Trump said he would "look at the possibility of giving concealed guns to gun adept teachers with military or special training experience" and suggested he was considering pay bonuses for educators who complete firearms training.

Three staff members at Stoneman Douglas school were killed during the shooting, including a football coach and security guard who was shot while trying to protect pupils from gunfire. The school's athletic director, a veteran who was deployed to Iraq in 2007, was also killed, along with a teacher who had unlocked his classroom door to let students in to hide moments before he was shot.