The reenactment of a 2018 mass shooting at a Florida high school will take place early next month as part of a civil lawsuit and will use live ammunition with a bullet safety device, a judge was told Thursday.

Circuit Judge Carol-Lisa Phillips endorsed an agreement reached by attorneys for victims' families and former Broward Deputy Scot Peterson to conduct the reenactment Aug. 4 at a three-story classroom building at Marjory Stoneman Douglas High School.

An ballistics expert for the families, former FBI agent Bruce Koenig, testified that live rounds make a different sound than blanks. A key issue in the lawsuit is what Peterson could hear during the shooting on Valentine's Day 2018, in which 17 people died and 17 more were wounded with an AR-15-style rifle.

"You want to imitate the situation as close as possible," Koenig said. Blanks, he added, are "almost as loud, but there definitely is a difference."

Peterson, the school's on-campus deputy, was acquitted last month of criminal charges accusing him of inaction during the shooting, but the civil case against him that makes similar accusations is proceeding.

Family attorney David Brill said the live rounds would be fired into a ballistic bullet trap that is commonly used at gun ranges and by law enforcement labs to catch the ammunition safely.

"It is in fact perfectly safe and controlled," Brill said.

Peterson's attorney, Michael Piper, said the agreement will mean only one reenactment rather than two as initially proposed. An attorney for the Broward County school board also endorsed the plan.

"We think this is the best way to approach it," Piper said. "We don't want to put the community through that twice."

The building, left virtually untouched since the shooting, will be demolished once the legal action is completed, school officials said. The reenactment would be based on school surveillance videos of the massacre that show second-by-second the actions and locations of Peterson and shooter Nikolas Cruz during the six-minute attack in which some 140 rounds were fired.

Victims and family members have taken grim tours of the building since the criminal trials ended, with the last visit to take place Thursday, officials said.

Peterson, 60, insists that echoes prevented him from pinpointing where the shots were coming from and that he would have charged inside if he had known Cruz's location. He retired shortly after the shooting, but was then retroactively fired.

Cruz, 24 and a former Stoneman Douglas student, received a life sentence last year after his jury could not unanimously agree that he deserved the death penalty.

Copyright 2023 AP. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.