#BREAKING #BSO school resource officer assigned to #StonemanDouglas was armed and did not enter building 12 as #NikolasCruz was inside in the process of killing 17 people @Telemundo51 pic.twitter.com/6r5uLSQ1li

— JRodriguez (@JRodzMIA) February 22, 2018

Marjory Stoneman Douglas High School had an armed and trained police guard at the school the day Nikolas Cruz killed 17 students and teachers. People have since questioned why the guard wasn't able to stop Cruz from committing the massacre. Broward County Sheriff Scott Israel solved that mystery minutes ago: BSO School Resource Officer Scot Peterson "never went in" to confront Cruz as the shooting occurred.

Israel said he suspended Peterson without pay after reviewing video footage, witness statements, and the officer's own statement. Peterson instead retired today to avoid further discipline.

When a BSO officer is told there's an active shooter in a building, Israel said, "we go in and address the target. That's what should have been done." Instead, Peterson waited "about four minutes" outside while Cruz murdered 17 people, the sheriff said. The New York Times reported yesterday that a local Coral Springs Police officer who arrived on the scene noticed Peterson taking cover outside in a stairwell.

Israel said today that Peterson was inside an office dealing with another student when the shooting began. The massacre lasted roughly six minutes.

Israel says Deputy "never went in"

— David Smiley (@NewsbySmiley) February 22, 2018

"He clearly knew there was a shooting?" one reporter asked.

"Clearly," Israel responded flatly. He then said he was "devastated, sick to my stomach" when he learned how his own officer reacted that day.

Peterson was at the building while Cruz was in the building, Israel says. What should he have done? "Went in. Address the killer. Kill the killer." https://t.co/J95y0J8pxh

— David Smiley (@NewsbySmiley) February 22, 2018

In 2015, the Sun Sentinel noted Peterson was living in a government-supplied mobile home on school grounds at Atlantic Technical College in Coconut Creek. He fought after a government audit labeled the program a waste of resources. Peterson had been a school resource officer around Broward County since at least 1996.

Israel yesterday announced that from now on, BSO school resource deputies will carry assault rifles. Today's news is certain to stoke the nationwide gun-control debate further: While gun advocates argue that a "good guy with a gun" could have stopped Cruz, it appears the professionally trained Peterson likely feared for his life and neglected to take action to stop the shooter.

The Orlando Police Department SWAT team was also heavily criticized for hesitating to confront Pulse nightclub shooter Omar Mateen in 2016. Shooting survivors said that had police confronted Mateen earlier, emergency medical personnel could have rushed in and saved more victims. (Orlando Police Chief John Mena defended his officers' conduct and a Department of Justice report said the response was "consistent with national best practices" for approaching a mass shooter.)

In the aftermath of Steven Paddock's rampage that left 59 people dead in Las Vegas last year, police there were criticized for waiting outside Paddock's hotel room for more than an hour as Paddock fired at the crowd below. In every case, the trained police personnel appeared to hesitate when confronted with an assault-style weapon.

This is a breaking story. This post will be updated.