Winkler was a soldier who participated in Operation: Deliverance.
Having survived the initial landings, Winkler was amongst the Rangers who rallied at the bus depot under the command of Captain Winters where they launched a succesful, albeit risky offensive to capture the bus depot from Chimeran forces.
During the bus depot offensive, Winkler was designated as a marksmen and was one of the two snipers that were seen with Captain Winters. All three men had been armed with salvaged L23 Fareyes.
During the battle, Winkler was told to protect Payton and his squad as they moved up to attack the two Sentry Guns in the furthest building, however, despite his best efforts, he ultimately failed as Payton and his squad were quickly mowed down by said Sentry turrets.