The armed school resource deputy at a high school in Parkland, Florida, did not intervene during the shooting that left 17 people dead, according to the local sheriff.
Deputy Scot Peterson resigned Thursday after being suspended without pay pending an internal investigation, Broward County Sheriff Scott Israel said.
Peterson allegedly waited outside the school building for about four minutes as the shooting unfolded last week. The deputy -- who was armed and in uniform at the time of the shooting -- never went in after taking a position on the west side of the building, Israel said at a Thursday afternoon news conference.
So what are school security protocols? To what extent are they armed and how are they trained to react in these situations? And what can schools do to make security more effective?
Alon Stivi, CEO of Direct Measures International, a security consultancy, tactical training and protective services company that works with schools; he also runs an active shooter survival course which is funded by the Department of Homeland Security