MIAMI — A former sheriff’s deputy was arrested Tuesday in connection with the controversial law enforcement response to the 2018 mass shooting at Marjory Stoneman Douglas High School in Parkland, Fla., the latest in a series of actions to hold police accountable for their response to an attack that left 17 people dead.
Scot Peterson, a former Broward County sheriff’s deputy who was the security officer assigned to the high school, faces 11 charges of neglect of a child, culpable negligence and perjury as a result of an investigation by the Florida Department of Law Enforcement, the authorities said. He was taken into custody and will be booked into the Broward County jail on a $102,000 bond.
“The F.D.L.E. investigation shows former Deputy Peterson did absolutely nothing to mitigate the M.S.D. shooting that killed 17 children, teachers and staff and injured 17 others,” the department’s commissioner, Rick Swearingen, said in a statement. “There can be no excuse for his complete inaction and no question that his inaction cost lives.”
Officials determined that Mr. Peterson, along with Sgt. Brian Miller, “neglected their duties,” and were both were terminated on Tuesday. Mr. Peterson was taken into custody after an administrative discipline hearing.
The criminal charges were an unusual instance of law enforcement officers being held criminally liable for failing to protect the public.
“This is the first time I have seen somebody so charged like this,” said Clinton R. Van Zandt, a former profiler with the F.B.I. and an expert on mass shootings. “I think that every police officer, sheriff and F.B.I. agent understands that you have to go to the threat and stop it and that we are no longer going to wait for SWAT or set up perimeters.”
The Department of Law Enforcement said its inquiry showed that Mr. Peterson, 56, did not investigate the source of the gunshots, retreated during the shooting while victims were still under attack and directed other law enforcement officers to remain 500 feet away from the building.
The sweeping 15-month investigation included interviews with 184 witnesses, along with reviews of video surveillance, to piece together what officials acknowledged was a slow and chaotic law enforcement response.
In January, Gov. Ron DeSantis suspended the Broward County sheriff, Scott Israel, citing neglect of duty and “incompetence.” He named as his replacement Gregory Tony, a former sergeant with the Coral Springs Police Department.
In his new position, Sheriff Tony oversaw an internal investigation of seven deputies at the department, including Mr. Peterson, and their handling of the Feb. 14, 2018, shooting.
“We cannot fulfill our commitment to always protect the security and safety of our Broward County community without doing a thorough assessment of what went wrong that day,” Sheriff Tony said. “I am committed to addressing the deficiencies and improving the Broward Sheriff’s Office.
Mr. Van Zandt said prosecutors appeared to be sending a message to the community that “we hear you are disappointed, and we will let the criminal justice system determine whether he made significant mistakes, whether perhaps he was a coward or not, or whether he acted properly with the information that he had.”
But, he contended, “it is going to be a challenge for prosecutors if the deputy stays with his story that his training did not teach him that, and that the circumstances did not dictate to him that his actions should have been to go in rather than facilitate the rescue of kids coming out and direct responding police officers coming in. In essence, he was directing traffic.”
Andrew Pollack, whose 18-year-old daughter, Meadow, died in the attack, said he welcomed Mr. Peterson’s arrest.
“It’s about accountability, and there’s to be more in Broward County,” said Mr. Pollack, who previously filed a wrongful-death suit against Mr. Peterson. “We knew all along that this guy did something very terrible. He let my daughter die, and a lot of other victims in the school — teachers and children — and he didn’t do his job.”
In an interview on Tuesday, Mr. Pollack said he and his lawyer had turned over records — including a deposition of Mr. Peterson — in the civil case to law enforcement officials to consider during their criminal inquiry.
Mr. Pollack said he hoped Mr. Peterson would be convicted and sentenced to a lengthy prison term. “He brought his Bible with him to the deposition,” he said. “Let him bring his Bible with him to prison. He can read the whole thing a bunch of times.”
He paused and added, “I don’t care what they do to this guy. Let him live with it.”