This CCTV captures an armed school police officer standing outside as the Florida shooting massacre unfolded.
Scot Peterson was assigned to protect Marjory Stoneman Douglas High School in Parkland.
But when monster former pupil Nikolas Cruz stormed the school armed with an assault rifle, Peterson failed to respond.
A 27-minute video release by Broward County Sheriff's Department shows Peterson staying outside as Cruz was inside shooting dead 17 staff and students.
Peterson resigned on February 22 rather than face suspension.
"The video speaks for itself. His actions were enough to warrant an internal affairs investigation," the sheriff’s office said in a statement accompanying the video’s release following a judge’s order on Monday.