"Following an investigation by FDLE, former Broward Sheriff’s Deputy Scot Peterson, 56, was arrested in Broward County today on seven counts of neglect of a child and three counts of culpable negligence and one count of perjury," the release said on Tuesday. "The arrest comes after a 15-month investigation".
Petersen was a safety officer at Marjory Stoneman Douglas (MSD) High School in Parkland, Florida, when last 17 February people were fatally shot by assailant Nikolas Cruz who was 19 at the time.
It remains the deadliest high school massacre in US history.
The investigation shows Peterson refused to investigate the source of gunshots, retreated during the active shooting as victims were being shot and directed other law enforcement arriving on the scene to remain 500 feet away from the building, the FDLE said.