Trial begins for Parkland school resource officer, 'Coward of Broward,' who stayed outside during shooting

Opening arguments are underway Wednesday in the trial of former Broward Sheriff's Office Deputy Scot Peterson, who is accused of failing to confront the Parkland school shooter. 

Prosecutors seek to convince a jury that Peterson failed to follow his active shooter training by remaining outside Marjory Stoneman Douglas High School on Feb. 14, 2018, while a gunman entered the building and killed 17 people. The police response to the massacre — the deadliest mass shooting at a high school in American history — was highly scrutinized, with critics focusing on the alleged inaction of Peterson, nicknamed the "Coward of Broward," who was armed but never went inside the building.

Peterson faces seven counts of child neglect, three counts of culpable negligence and one count of perjury related to the people who were killed or injured on the third floor of the school building.

Those killed include Meadow Pollack, Cara Loughran, Peter Wang, Jaime Guttenberg, Scott Beigel and Joaquin Oliver.

SHERIFF'S DEPUTY CHARGED WITH FAILING TO ACT DURING PARKLAND SHOOTING IS EAGER FOR TRIAL

The injured were Marian Kabachenko, Stacy Lippel, Kyle Laman and Anthony Borges. 

Peterson's defense attorneys claim the school resource officer did not know where the shots were coming from and say more than 20 witnesses will support his recount of the confusion on that day. The defense also argues that Peterson had no legal obligation under Florida law to enter the building and confront the shooter.

If convicted on all counts, Peterson faces nearly a century in prison and the loss of his $104,000 annual pension. 

On Monday, Peteson said he was looking forward to his trial and expressed confidence that the evidence presented by his legal team will show he did everything possible to help during the shooting.

FLORIDA JUDGE IN PARKLAND SHOOTER TRIAL REMOVED FROM DEATH PENALTY CASE FOR HUGGING PROSECUTOR

"I want the truth to come out and if it is going to be through a trial, so be it. I’m eager," said Peterson.

He continued, "Not only the people in Florida, the country, most importantly the families, they need to know the truth about what happened, because unfortunately it has never been told."

FATHER OF PARKLAND SHOOTING VICTIM SPEAKS OUT AGAINST SHERIFF TRYING TO GET REINSTATED: 'NO INTEGRITY AT ALL'

Peterson, 55, was widely criticized for his actions and Broward Sheriff Scott Israel opened an internal investigation. The deputy resigned and retired on Feb. 23, "rather than face possible termination."

The former deputy stood by his actions after the shooting. His lawyer said in a statement at the time that "the allegations that Mr. Peterson was a coward and that his performance, under the circumstances, failed to meet the standards of police officers are patently untrue."

Fox News' Timothy H.J. Nerozzi, Nicole Darrah and The Associated Press contributed to this report.