PARKLAND, Fla. (WFLA) – The former Broward County deputy who was the school resource officer at Marjory Stoneman Douglas High School during last year’s deadly mass shooting has been arrested on several counts of child neglect.

The FDLE announced Tuesday they had arrested 56-year-old Scot Peterson on seven counts of neglect of a child, three counts of culpable negligence and one count of perjury. The arrest is the result of a 15-month investigation into law enforcement’s actions during the mass shooting at Stoneman Douglas.

“The FDLE investigation shows former Deputy Peterson did absolutely nothing to mitigate the MSD shooting that killed 17 children, teachers and staff and injured 17 others,” FDLE Commissioner Rick Swearingen said in a statement. “There can be no excuse for his complete inaction and no question that his inaction cost lives.”

Authorities say a former student walked into Stoneman Douglas High School on Feb. 14, 2018 and opened fire. The FDLE investigation found Peterson refused to investigate the source of the gunshots and retreated while victims were being shot, a spokesperson says.

Investigators say Peterson also directed other law enforcement officers responding to the scene to stay 500 feet away from the building.

Peterson was arrested and booked into the Broward County Jail. The Broward State Attorney’s Office will prosecute the case.

Broward County Sheriff Gregory Tony also released a statement Tuesday to officially announce the termination of Deputy Peterson.

“All the facts related to Mr. Peterson’s failure to act during the MSD massacre clearly warranted both termination of employment and criminal charges. It’s never too late for accountability and justice,” Sheriff Tony said.

In addition to terminating Deputy Peterson, Sheriff Tony also terminated Sgt. Brian Miller. Tony’s statement said both men had neglected their duties at Stoneman Douglas High School.

Tony was appointed sheriff earlier this year by Gov. Ron DeSantis after the governor suspended Scott Israel, who served as sheriff at the time of the shooting. DeSantis said Israel had “repeatedly failed” and “demonstrated a pattern of poor leadership.” Israel sued DeSantis after being suspended, saying the governor ousted him for political reasons. A judge later dismissed that lawsuit.