The Broward County Sheriff's Office is investigating reports its deputies on scene at Marjory Stoneman Douglas High School stayed outside while there was an active shooter inside the building.
One deputy, the school's resource officer — who was armed and on campus in a different building — resigned after he was suspended without pay following reports he didn't enter the building to engage the shooter.
Now, three more deputies who arrived on the scene later are under investigation. CNN reported Coral Springs police officers arrived to find all four deputies taking cover behind their vehicles with their weapons drawn.
Sheriff Scott Israel made clear what the resource officer should have done: "Went in. Addressed the killer. Killed the killer."
Studies of the 1999 Columbine shooting have given law enforcement a better sense of how to engage an active shooter. Traditional tactics like setting up a perimeter, containment and hostage negotiation are now understood to lead to a much higher casualty rate than engaging a shooter as quickly as possible.
A common tactic since Columbine is called "Immediate Action Rapid Deployment." That's when a number of officers, typically four, enter a building, often in a diamond formation. That allows the group to end the threat more quickly than officers working alone or using a different tactic.
It's not yet clear whether or not Broward County deputies were trained in this tactic or something similar.
Additional reporting from Newsy affiliate CNN.
