Steve Burnside is Claire Redfield's partner in the game Resident Evil Code: Veronica.
Steve was imprisoned in the Rockfort Island's facility alongside his father, a former Umbrella employee. He escapes from his cell during the viral outbreak. Steve was initially hesitant to trust Claire while reluctantly cooperating with her, but gradually cares for her after being forced to kill his own father when he becomes infected.
Steve and Claire eventually end up in Umbrella's Antarctic Facility, where he is captured by Alexia and infected with the T-Veronica Virus to be compelled to kill Claire. Though he mutated into a nearly invulnerable monster armed with a giant, ceremonial axe, Steve eventually regained control of himself and is fatally injured protecting Claire from Alexia's tentacles and reverts while professing his love to Claire in his final moments.
Steve's body were later taken by Albert Wesker to extract the T-Veronica virus from his body. In The Darkside Chronicles it is revealed that Wesker contacted the drug baron Javier Hidalgo and took a sample of T-Veronica from Steve's corpse in order to sell the virus for Hidalgo's ailing daughter, Manuela.