Originally Published: 26 JUN 23 06:01 ET

Updated: 26 JUN 23 17:15 ET

By Dakin Andone and Denise Royal, CNN

(CNN) — Jurors began deliberations Monday in the trial of a former school resource officer who stayed outside during the February 2018 mass shooting at Marjory Stoneman Douglas High School.

Prosecutors earlier urged the group to find Scot Peterson guilty on all counts, contending his alleged inaction contributed to the deaths of six victims and the injuries of four others in the attack. His attorneys have contended the former deputy did nothing wrong and couldn’t tell where the shots were coming from. Seventeen people died in the shooting.

Both prosecutors and Peterson’s attorneys agreed to remove a juror who, according to the state, had attended the penalty phase in the trial of convicted Parkland school shooter Nikolas Cruz and knew victims’ advocates in the prosecution’s office. The juror was replaced by an alternate.

The judge plans to allow the jury to deliberate until 6 p.m. ET Monday.

The state has accused Peterson, 60, of failing to confront the gunman according to his active shooter training, instead taking cover for more than 45 minutes outside the school’s three-story 1200 building during the attack, which remains the deadliest high school shooting in US history.

“In that moment, while he stood at those doors, every student and every teacher on the third floor was still alive,” Assistant State Attorney Kristen Gomes said Monday during closing arguments. “In that moment, choose to go in, or choose to run. And Scot Peterson chose to run.”

Closing arguments concluded Monday afternoon before jurors started their deliberations.

Peterson has pleaded not guilty to 11 charges, including seven counts of felony child neglect and three of culpable negligence derived from each of the 10 victims fatally shot or wounded on the 1200 building’s third floor: Teacher Scott Beigel and students Cara Loughran, Meadow Pollack, Joaquin Oliver, Jaime Guttenberg and Peter Wang were all killed, while teacher Stacey Lippel and students Kyle Laman, Marian Kabachenko and Anthony Borges survived.

“He left behind an unrestricted killer to spend the next four minutes and 15 seconds wandering the halls at his leisure,” Gomes said. “Because when Scot Peterson ran, he left children trapped inside of the building with a predator unchecked. (From) 2:23 p.m. forward, that predator would fire 70 rounds from the moment that man made the decision not to enter.”

Defense attorney Mark Eiglarsh, meanwhile, said in his own closing argument his client – a former deputy for the Broward Sheriff’s Office and the first law enforcement officer on scene that day – did nothing wrong.

Peterson, who retired as criticism of his alleged failure grew, did not enter the 1200 building because he could not tell where the gunshots were coming from due to echoes on campus, the defense argued, pointing to the testimony of other witnesses who also expressed confusion.

“Two dozen witnesses came in here one by one and told you they couldn’t tell from the sounds precisely what area we’re talking about,” defense attorney Mark Eiglarsh said Monday, “The best you could do is narrow it down to that general area around the 1200 building.”

“(The state’s) entire case hinges upon this erroneous belief that he knew that there were kids in that 1200 building being shot by this monster,” Eiglarsh said, asking jurors for a verdict of not guilty. “And that wasn’t proven because it didn’t happen.”

Peterson also faces one count of perjury for telling investigators afterward that he didn’t see students fleeing the 1200 building and that he heard only two or three gunshots after arriving at the scene while other witnesses said they’d heard more. The state believes the evidence shows both statements were untrue. He faces up to life in prison if convicted on all counts.

Seventeen people – 14 of them students – were killed in the shooting, and 17 others were wounded. Peterson was not charged for the victims on the first floor, however, because he had not yet arrived on scene. No one was killed on the second floor.

Law enforcement aim is to stop shooter, witnesses said

The case is unusual, in part because it marks the rare prosecution of a law enforcement officer over his response to a mass shooting, highlighting expectations for first responders at a time when America’s gun violence epidemic shows no signs of abating.

But it’s also notable because prosecutors brought child neglect charges against Peterson under a Florida statute which applies to caretakers, arguing in his capacity as a school resource officer, Peterson was responsible for the protection of the high school’s students and staff. The defense previously insisted the statute didn’t apply to Peterson, but the judge ruled that determination would be made by the jury.

On the morning of February 14, 2018, parents taking their kids to school would have had the chance to see Peterson on campus in uniform, Gomes said Monday, adding those parents “would have been absolutely correct to assume that that man’s only priority was the safety of their child.”

Because Peterson “wasn’t just on campus to catch kids with fake IDs, to work on the vaping problem that they were having,” she said. He was an “extensively trained” officer who was “there by contract, by job description for the safety of those kids.”

Prosecutors from the Broward State Attorney’s Office rested their case last Wednesday, after almost two weeks of testimony. It included a number of witnesses who testified they knew what Peterson – holding what the state called a “position of cover” – claims he did not: The gunshots were emanating from the 1200 building.

“When I looked at him, he just had a blank look on his face,” former school Security Specialist Kelvin Greenleaf, who arrived at the scene with Peterson, said during his testimony last week. “There was so much going on, and I can imagine the stress and the pressure that he was under … and I just don’t think he realized pretty much what was going on.”

The state also called multiple law enforcement officers who told the jury their training dictated they move toward the sound of gunfire to confront a possible shooter or shooters – a directive widely adopted in the wake of the 1999 shooting at Columbine High School in Colorado, Lt. Col. Samuel Samaroo of the Broward Sheriff’s Office, who was involved in the department’s training, testified.

Broward County Sheriff’s Detective John Curcio, the lead investigator of the case against the shooter, similarly testified law enforcement is “supposed to go towards the shots” to locate and confront a gunman.

“The goal is to stop (the shooter) from killing people,” said Curcio. “And that doesn’t mean killing him. It means slowing him down, it means distracting him, it means anything so those kids can find safety.”

Prosecutors don’t believe Peterson was required to kill the shooter, Gomes said Monday, telling the jury, “The state did not expect Scot Peterson to go on a suicide mission.”

But he had a duty to “confront and engage,” she said, adding, “What was expected was for Scot Peterson to value the lives of those children as much as he clearly valued his own.”

Defense rested after two days

Defense attorney Eiglarsh called several witnesses out of turn during the state’s case but rested on Friday after two straight days of testimony including witnesses – former students, staff and members of law enforcement – who supported Peterson’s claim it was difficult to hear where the gunfire was coming from.

“The issue is whether he knew, and the evidence fails to show it,” Eiglarsh said Monday.

Peterson was at the scene for the last four minutes and 15 seconds of the shooting, which lasted about six-and-a-half minutes in total, Eiglarsh has emphasized.

Broward County Sheriff’s Deputy Arthur Perry, who responded to the scene and said he stayed outside the building where the shooting occurred, testified he did not learn the details until later in the evening via news reports.

“I didn’t learn there was a shooter with victims inside the 1200 building until about 7 p.m. that night, when I looked on Fox News on my phone because there was no communication telling us what was going on,” Perry said, underscoring defense allegations of radio problems contributing to a communications breakdown at the scene, preventing critical information from being shared between agencies.

Perry’s testimony aligned with other defense witnesses, including former students and school staff, like teacher Suzanne Camel, who taught in the nearby 700 building. She told jurors the gunshots were incredibly loud and sounded like firecrackers being thrown at her, though she said under cross-examination she’d never heard gunshots before.

Student Tyler Jarboe said he believed gunshots were coming from the west stairwell of the 700 building, where he was in class. Echoes are prominent in that part of campus, he said.

Eiglarsh also called to the stand Jeffrey Morford, then an assistant principal at Marjory Stoneman Douglas High School, who said it was Peterson who ordered a Code Red, perhaps preventing further deaths and injuries among the rest of the student body. The state called the testimony into question on cross-examination: In a 2018 deposition, Morford said he did not recall who ordered the Code Red.

Morford also said Peterson ordered him and Greenleaf to review security footage as the shooting unfolded in hopes of locating the gunman. Taken together, the defense contended, the actions and others illustrate Peterson was not negligent but actively responding to the attack.

“To sit in the calmness of a courtroom that is chill and mellow and try to go back and Monday morning quarterback is unfair and unjust,” Eiglarsh said Monday.

Only one person was responsible for the shooting, Eiglarsh has argued: The shooter, who pleaded guilty to 17 counts of murder and 17 counts of attempted murder and was sentenced to life in prison without parole.