The release of the video comes less than a month after Broward County Sheriff Scott Israel told ABC News that video showed Peterson "arrive at the west side of Building 12, take a position" but never go in.
Authorities released surveillance video today showing what happened outside Marjory Stoneman Douglas High School during the Valentine's Day massacre that killed 17 people.
Gunman Nikolas Cruz opened fire on people at his former high school in Parkland, Fla., and armed deputy Scot Peterson did not confront him from inside where the bulk of the massacre occurred. It appears that they get into a golf cart at 2:22:45 - around the time, according to BSO logs, that Cruz has already been in the 1200 building on the campus and has already fired many rounds.
The police radio recordings showed that the Coral Springs police officers were the first to enter the school building after confirming that Broward County Sheriff's Office deputies had not gone in.
Broward County Sheriff Scott Israel said Peterson was suspended without pay, and chose to resign.
Judge Elizabeth Scherer then entered the not-guilty plea on his behalf for 17 counts each of first-degree murder and attempted murder for the February 14 shooting spree in Parkland.
In the newly released clip, Peterson can be seen outside the school as the shots began, he and another man knock on a door before turning and walking in the other direction.
"The video speaks for itself". BSO policy calls for deputies to engage an active shooter and eliminate the threat, but does not explicitly say an officer "must" enter a building. He also radioed the sheriff's office, issuing a warning about the incident.
Peterson's attorney, Joseph DiRuzzo, did not immediately respond to a request for comment.
"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.
BSO initially resisted release of the video, but at a hearing in the media lawsuit last week, changed course and agreed the footage should be made public.
The footage does not show Cruz, who shot up the inside of the school for about six minutes.