Scot Peterson, the police deputy at Florida’s Marjory Stoneman Douglas High School where 17 people were gunned down earlier this year, said he’s dissected that tragic day over and over, and doesn’t understand how people are claiming he did nothing.

Breaking his silence in an interview with The Washington Post released Monday, Mr. Peterson said it was his job as a police officer to find the gunman, Nikolas Cruz, but he failed to do so.

“I’ve cut that day up a thousand ways with a million different what-if scenarios, but the bottom line is I was there to protect, and I lost 17,” he said.

The gunman killed 17 people in a mass shooting on Valentine’s Day and is currently being held in the Broward County Jail awaiting trial.

“How can they keep saying I did nothing?” Mr. Peterson questioned. “I’m getting on the radio to call in the shooting. I’m locking down the school. I’m clearing kids out of the courtyard. They have the video and the call logs. The evidence is sitting right there.”

Mr. Peterson resigned shortly after the mass shooting following public criticism from Broward County Sheriff Scott Israel.

Surveillance video revealed Mr. Peterson waiting outside the school as the gunman was still inside shooting.

Sheriff Israel said the school officer should have “went in. Addressed the killer. Killed the killer.”