Crissom was an officer in the Corellian Security Force during the Galactic War between the Galactic Republic and the resurgent Sith Empire. During Corellia's war against the Empire, Crissom served alongside Hanley, Davit, and Officer Silas in attacking Imperial forces that have taken the Corellian Security Force Academy in Axial Park. They were soon rescued by Republic forces before they were overrun by the Empire.