When a shooter opened fire in 2018 at a school in Parkland, Florida, a former sheriff's deputy was put on trial for failing to provide for the safety of the students.
When the Marjory Stoneman Douglas High School attack occurred, Scot Peterson was the police officer on duty.
According to the National Association of School Resource Officers, he is the first US officer accused of being slow to react to a school shooting.
Up to 97 years in prison are possible for the 60-year-old.
He is accused of 11 offenses, including 11 counts of perjury and seven felonies for felony child neglect.
According to the prosecution, Mr. Peterson failed to use his active-shooter training to reduce casualties during the six-minute attack despite having a handgun and not donning a bulletproof vest.
As shots were being fired, he did not enter the structure, according to video.
The deadliest school shooting in US history still left 17 people dead and 17 others injured.
In order to convict Mr. Peterson, the prosecution must convince the jury that both he knew the shooter was inside the building and that his alleged inaction put students in danger. Moreover, they need to demonstrate that he had the right to care for the students.
Insisting he would have gone inside the building to confront the attacker, Mr. Peterson has maintained he believed the shots were being fired by a sniper outside.
Defense lawyers have stated that they will contend that their client does not meet the statutory definition of "caregiver" in this situation. Usually, parents or daycare providers are charged with violating the neglect law.
For allegedly lying under oath to investigators about his actions that day, Mr. Peterson is charged with misdemeanor perjury.
Peterson "did all he could to save lives," according to a statement from his lawyer Mark Eiglarsh on Tuesday.
"We have overwhelming evidence proving that my client didn't know precisely where the shooter was during the attack and also, of the numerous actions that my client took during the attack to save lives," the attorney claimed.
Following the attack, Mr. Peterson retired after 32 years as a deputy. He was charged in June 2019.
Additionally, if found guilty, he would forfeit his $104,000 (£83,500) yearly pension.
Mr. Peterson "did absolutely nothing to mitigate" the shooting, according to a Florida Department of Law Enforcement investigation.
A total of 140 shots were fired by the shooter, 75 of which were fired after Mr. Peterson arrived on the scene, according to their investigation.
His detractors, which included the then-President Donald Trump, called him a coward.
After confessing to the murders, the attacker was given a life sentence without the possibility of parole last year.
