On the night of King S'turnn J'axx's murder, R'ohh K'arr was on guard duty at the Royal Palace gate. He paid little attention to the A'ashenn workers coming in, failing to notice that one was a G'arrunn in disguise. Following the murder, he gave a memory record of the night as part of the investigation.[5]
K'arr was convinced Ma'alefa'ak was behind the explosion, despite Miss Martian's insistence that they had caught him before he did anything. K'arr and his men took Ma'alefa'ak into custody, with the terrorist's family following.[4]
K'arr, R'ess E'dda and Queen J'arlia were in the Grand Hall of the Royal Palace when Prince J'emm J'axx brought Superboy and Beast Boy to investigate the site of King S'turnn's murder.[6]
K'arr was on-duty at the Royal Arena during Prince J'emm's birthday celebration. Following the arrest of S'yraa S'mitt for King S'turnn's death, he informed Queen J'arlia and R'ess E'dda that they had a full confession. He remained on-duty once the festivities resumed, and helped evacuate the Queen when a bomb was discovered.[5]
Roh Kar was an early Green Martian, debuting in Batman #78 in 1953, two years before J'onn J'onzz. He was called "the Manhunter from Mars", a lawman who called on Batman and Robin to bring a Martian criminal to justice. He was later reintroduced as an ally of Martian Manhunter under the name Roh'kar.
