Scot Peterson, the ex-law enforment officer at Marjory Stoneman Douglas High, loses his appeal

Marjory Stoneman Douglas High School in Parkland, Florida.

An appeals court Thursday upheld a ruling that allowed civil lawsuits to move forward against Scot Peterson, a former Broward County sheriff’s deputy and school law enforcement officer who was accused of failing to properly respond during the 2018 mass shooting at Parkland’s Marjory Stoneman Douglas High School.

Without explanation, a panel of the 4th District Court of Appeal rejected Peterson’s argument that a circuit judge should have granted summary judgment in his favor.

The lawsuits were filed by victims’ family members and were consolidated in circuit court.

Summary judgment would have ended the lawsuits and averted a potential trial.

Nikolas Cruz, a former Marjory Stoneman Douglas student, killed 17 students and faculty members in the shooting.

In part, Peterson’s attorneys argued he did not have a legal “duty of care” and pointed to a state sovereign immunity law that generally shields government employees from personal liability for on-the-job actions.

“Florida law is unequivocal that whether it is by reason of a lack of legal duty, by application of statutory immunity, or both, as a governmental employee, Peterson cannot be held liable for an alleged failure to stop Cruz from committing mass murder,” Peterson’s attorneys wrote in a brief at the appeals court. “Peterson was entitled to final summary judgment in his favor.”

But the plaintiffs’ attorneys wrote in a brief that Peterson had “an affirmative duty to respond to this situation by locating, engaging, and neutralizing” Cruz.

“A police officer who knows that a murderer is shooting a gun and likely killing people in a school has a mandatory operational-level obligation to respond,” the plaintiffs’ brief said. “That is his job. A police officer may have discretion to arrest or not arrest a drunk driver, but he has no discretion to walk by a store in which he sees that a robbery is being committed, or a school in which shots are being fired.”

The appeals court panel was made up of Judges Dorian Damoorgian, Spencer Levine and Alan Forst.