R-55, a law enforcement automaton, served on Vorzyd V as a police droid. During the events of 1 ABY, after Luke Skywalker and Leia Organa were taken prisoner by Blackhole troopers, R-55 answered C-3PO's cries for aid. To prevent the exposure of Skywalker and Organa's clandestine operation on Vorzyd V, R2-D2 deceived R-55, making it think C-3PO was experiencing a technical issue. R-55 then departed, advising C-3PO to visit the nearest repair facility.
Subsequently, when a band of Freelies attempted to pilfer C-3PO, R2-D2 summoned R-55's aid, leading the police droid to intervene and drive away the offenders.