PARKLAND — Court officials and ballistics experts gathered at Marjory Stoneman Douglas High School on Friday to reenact the deadliest high school shooting in U.S. history.

The three-story building where a gunman killed 17 people and wounded 17 others in 2018 has remained largely untouched since the day of the shooting. Cordoned off behind a 15-foot chain-link fence, it teemed with activity Friday — not long before officials say they plan to demolish it for good.

Technicians set up outside of the building to capture the sound of live gunfire ricocheting through its halls a second time. The reenactment is part of a civil lawsuit against former Broward County Sheriff's Deputy Scot Peterson, who stood outside while a gunman fired at students and teachers trapped inside locked classrooms and hallway alcoves for more than six minutes on Feb. 14, 2018.

Peterson came within feet of the building’s door and drew his gun, then backed away.

A jury acquitted Peterson in June of all criminal charges stemming from his failure to confront the gunman. Attorneys representing the families of Stoneman Douglas victims and survivors say Friday's reenactment will prove Peterson could tell where the gunfire was coming from but chose to stay outside anyway.

Mark Eiglarsh, the defense attorney who represented Peterson during his criminal trial, called the reenactment traumatic and unnecessary. He pointed to the testimony of law-enforcement officers, students and staff members who said the reverberation and echo of the gunfire made it difficult to pinpoint where the sound was coming from.

Some said they thought the shots were coming from the football field, Eiglarsh said — hundreds of yards away from where the shooter actually was. He called Friday's reenactment an attempt to manufacture evidence "that cannot possibly be re-created with any degree of accuracy."

"It’s insulting to those jurors, to the criminal justice system, and unnecessarily traumatic to all the neighbors in that area," he said.

A bipartisan group of Congress members and victims' families toured the yellow-and-gray building hours before the reenactment began Friday. They waited in a single-file line, like students heading to class, before Broward County sheriff's deputies opened the door.

Scenes from "a war zone" awaited them inside, said U.S. Rep. Jared Moskowitz, D-Fla.

"You can read about it all day long. You can debate it all day long," he told members of the media afterward. "But it's not the same as going and walking through the school."

Reporters who toured the building during the gunman's sentencing trial last year said it was like walking through a graveyard. The walls and floors are still stained with blood. Items from the students, including Valentine’s Day gifts, lay untouched on each of its three floors.

The tour, inspired by a call to action by the father of shooting victim Alex Schachter, ended at about 9:45 a.m. Lawmakers reconvened at the Marriott Coral Springs hotel afterward — the same place parents waited to learn whether their children survived the shooting.

There, Moskowitz, a Parkland native and Stoneman Douglas alumnus, led a closed-door discussion with lawmakers on how to prevent future bloodshed.

"We need to continue to get together to get it done," said U.S. Rep. Mario Diaz-Balart, a Republican from Miami. "If we can't work together on this, what the heck are we doing?"

He struggled to describe what he had seen in the halls of the freshman building, calling it the "one of the most horrific acts of evil" a human could ever do.

The building has been preserved as an active crime scene since the day of the shooting. State lawmakers agreed two days after the massacre to pay to have the building demolished but have had to wait for the criminal trials against the gunman and Peterson to end. The Broward County School District has said the demolition will not be completed before school begins Aug. 21.

Joaquin Oliver, who was shot to death on the third floor, would have turned 23 on Friday.

Valentina Palm can be reached at[email protected] or on X, the former Twitter @ValenPalmB. Reach Hannah Phillips[email protected].