The former Broward County, FL, 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, reports WFLA.

The Florida Department of Law Enforcement 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."

Broward County Sheriff Gregory Tony announced that he formally fired Peterson and Sergeant Brian Miller, who were both found to have “neglected their duties” by internal investigations at the office, reports WLRN.