An Ryd

Murdered by an insane Brainiac 5, who framed Ultra Boy for the crime.

From Who's Who in the Legion of Super-Heroes 1:

A former schoolmate and girl-friend of Jo (Ultra Boy) Nah's, An grew up to become a criminal, participating in a scheme to lure Jo home to Rimbor so he could be captured by her conspirator, Pulsar Stargrave. An was double-crossed by Stargrave and was murdered in the hotel room where she was to meet Jo. Because Stargrave used a heat weapon which mimicked Ultra Boy's flash vision, Ultra Boy was suspected to be her killer. The Legionnaires took Jo into their custody, but he he escaped and, with Chameleon Boy's help, cleared himself.