It was meant to be the police officer of tomorrow. It was supposed to save lives. When Doctor Thomas Rizzo created the Zone Enforcement Response Option construct, it was with the best intentions. Rizzo, also a police officer that graduated the academy at the top of his class, made Officer Z.E.R.O. to handle the most hazardous situations in order to prevent loss of human life, like his older brother Daniel who died in the line of duty. Code: Blue
was supposed to observe the robot as he performed menial police functions in a test run, but something went wrong when Z.E.R.O. detected a group of individuals that were up to no good. It wouldn’t obey orders and proceeded to kill the men when they wouldn’t cease firing on him. It then turned on the members of Code: Blue when they disapproved of its actions and began shooting at them. Lieutenant Stone stood alone against the metal monstrosity, just as "Mother" Majowski, another member of Code: Blue, figured out that the robot was feeding off the subconscious resentment Doctor Rizzo harbored for the police department because of the death of his brother. Officer Z.E.R.O. was about to kill Stone when its creator determined that the only way to stop the robot was to cut off the feed to its brain. Doctor Rizzo claimed that his brother died a hero and he could do no less, so he took his gun and shot himself in the head. Z.E.R.O. keeled over lifeless, and the life of Lieutenant Stone was spared. The remains of the robot were cleared away, and it can be assumed that the police will not commission another robot like Officer Z.E.R.O.