Sgt Brian Miller was placed on suspension before being fired from job in 2019

He was terminated after his actions during Parkland shooting were investigated

Investigation found that Miller cowered behind car while Nikolas Cruz, who murdered 17 people at Marjory Stoneman Douglas High School in February 2018

An arbitrator dismissed the case against Miller after ruling that his due process rights were violated when he was fired; he will receive back pay after his firing