A Florida sheriffs deputy who resigned for staying outside Marjory Stoneman Douglas High School during last months mass shooting also warned other officers to stay away, according to newly released police radio recordings.

Do not approach the 12 or 1300 building, Stay at least 500 feet away at this point, ex-Deputy Scot Peterson says on police radio minutes after the shooting had stopped and students and staff lay dying.

The Feb. 14 massacre killed 17 people and wounded more than a dozen. Peterson, an armed school resource officer hired to protect students on the Parkland, Florida, campus, was forced to resign after it was discovered he did not engage the shooter. The police radio recordings, along with a timeline of events released Thursday by the Broward County Sheriffs Office, suggest Peterson may have hampered the ability of other officers to help victims.

Peterson can be heard on the recordings giving commands as he waits outside the school and the first officers arrive.

Get the school locked down, gentlemen! he shouts.