PARKLAND, Fla. – The school resource deputy who was on patrol at Marjory Stoneman Douglas High School in Parkland, Florida, on Feb. 14 resigned Thursday. His choice to resign/retire comes with cause after video surveillance showed he never entered the school, even though he “clearly” knew there was a shooting taking place, officials said.

Deputy Scot Peterson, of the Broward County Sheriff’s Office, was stationed on the school’s campus when the shooter opened fire with an AR-15 rifle, leaving 17 people dead and others wounded, reported Fox News.

During a Thursday press conference Sheriff Scott Israel said video showed Peterson arriving at the west side of the building where the shooting took place. Peterson, Israel said, took up a position but “never went in.”

Peterson was armed and in uniform during the shooting, but never entered the building despite “clearly” knowing a shooting was happening, according to the sheriff.

Sheriff Israel said he believes Peterson remained outside of the building for roughly four minutes, while the shooting in total lasted around six minutes. Moreover, Israel said the deputy never fired his weapon.

Israel told reporters he’s “devastated. Sick to my stomach. There are no words.”

When asked about what law enforcement agencies entered the building first, and at what time, Israel said that it “doesn’t matter who went in first” or “what order you went in.”

“What matters is that when we, in law enforcement, arrive at an active shooter, we go in and address the target,” the sheriff said. “And that’s what should’ve been done.”

Peterson, according to Israel, should’ve “went in. Address the killer. Kill the killer.”

The sheriff said that he suspended Peterson without pay pending an internal investigation, but the deputy apparently decided to retire on the spot. According to his separation papers filed Feb. 22, 2018, he’s been on duty since July 22, 1985.

It is unknown if the mass murder and subsequent internal affairs investigation precipitated his plans to retire.

In 2014, Peterson was named School Resource Officer of the Year in Parkland, WSVN reported. The district stated “Deputy Peterson has proven to be reliable in handling issues with tact and judgment.”

Two other deputies from the Broward County Sheriff’s Office have been placed on restrictive duty as officials investigate “whether or not they could have done more, should’ve done more.”

Their restricted assignments come as the bureau found it responded to 23 calls regarding the accused murderer or his brother since 2008. In two of the instances, Col. Jack Dale said, protocol might not have been followed.

Israel said an investigation remains ongoing.