Deliberations continue over then-Parkland school resource officer's fate in rare trial over police conduct in a mass shooting

Jurors concluded their second day of deliberations Tuesday evening in the trial of the former school resource officer who stayed outside during the 2018 mass shooting at a Parkland, Florida, high school - the culmination of a rare prosecution of a law enforcement officer over his response to a mass shooting.

Deliberations are expected to resume Wednesday morning.

Prosecutors say Scot Peterson, 60, ignored his training and common sense and chose to do nothing as 17 people, including 14 students, were gunned down at Marjory Stoneman Douglas High School in the deadliest high school shooting in US history. His attorney argued the then-deputy for the Broward Sheriff's Office didn't enter the building where the carnage unfolded because he couldn't tell where the shots were coming from.

"His job was to go and investigate and make his presence known, and that simply did not happen," Assistant State Attorney Christopher Killoran said in closing rebuttal arguments Monday.

The verdict is anticipated as America's scourge of mass and school shootings drags on, with about 200 attacks on K-12 campuses since the Valentine's Day massacre at the Parkland school. Some 331 shootings with at least four wounded, not including a shooter, have been recorded so far this year, Gun Violence Archive reports.

After about 3 1/2 hours of deliberating, jurors asked Tuesday morning to view "poster-sized evidence" and other visual aids used by the state and defense during their presentations. The court declined to provide the visual aids since they were not introduced into evidence, and state Judge Martin Fein told jurors they had all the evidence introduced by both sides.

Jurors asked another question Tuesday afternoon regarding a password needed to access a hard drive so they could review a piece of the state's evidence. Prosecutors provided jurors with instructions and the password.

Peterson is accused 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 before the gunman was apprehended.

"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. "In that moment, choose to go in, or choose to run. And Scot Peterson chose to run."

Peterson has pleaded not guilty to eleven counts, including seven felony counts of child neglect and three misdemeanor counts of culpable negligence for his alleged inaction to stop the shooter. He also faces one misdemeanor count of perjury for lying to investigators about the number of gunshots he heard after arriving at the scene of the shooting, according to prosecutors.

The charges reflect the deaths and injuries of seven students and three school employees on the third floor of the 1200 building. Peterson was not charged in connection with the victims on the first floor because he had not yet arrived on scene. No one was killed on the second floor.

Peterson, who retired as criticism of his alleged failure grew, never knew where the shooter was, defense attorney Mark Eiglarsh told jurors, pointing to other witnesses who testified they could not narrow down where the deadly shots originated.

"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," Eiglarsh said in his closing argument Monday.

And even if Peterson had known where the shooter was, speculation he could have made a difference is false, Eiglarsh argued.

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."

Only one person was responsible for the shooting, Eiglarsh 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.

Peterson's trial included testimony from former students, staff and members of law enforcement who supported the ex-deputy's claim it was difficult to hear where the gunfire was coming from. Jurors also heard from witnesses who testified they knew the shots were emanating from the 1200 building, as well as law enforcement officers who testified their training dictated they move toward the sound of gunfire to confront a possible shooter.

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."

But Peterson "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."

Eiglarsh has emphasized Peterson was at the scene for the last 4 minutes and 15 seconds of the shooting, which lasted about 6 1/2 minutes. Peterson also arrived at the scene without a bulletproof vest or rifle and called for measures to lock down the school, the attorney told jurors.

"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," he added.

CNN's Nouran Salahieh contributed to this report.