At some point of his life, Crosby studied and became a computer engineer, and later he joined the Star City Police.
Working for Ricardo Diaz
A while after Ricardo Diaz killed Cayden James and started taking over Star City, Crosby started working for him. After Diaz's USB fell during a fight with Mr. Terrific, Diaz demanded for Crosby's help to make sure the data was fine, but told Crosby not to look on the data, and threatened with killing Crosby's grandmother.
Crosby detected that a hacker was trying to break into his network and clone Diaz's data, so he told Diaz and started looking the location of the cloned data, which he accomplished a few hours later.
After that, Crosby witnessed Lydia Cassamento's murder, and was ordered to clean up that mess.
The Fall of Diaz's Empire
Green Arrow, along with the FBI and his team, entered the precinct where Crosby worked and defeated all the corrupt cops inside it in a short fight. Crosby was asked by Green Arrow for Diaz's location, but Crosby didn't answer. Along with the rest of the SCPD, he was arrested by the FBI.