Former Constantine actor Charles Halford has been cast as Jemm in CBS's Supergirl. Halford played Chas Handler on the short-lived NBC series as well as a minor character in ABC's Marvel's Agents of S.H.I.E.L.D.
In comic books, Jemm is billed as the "Son of Saturn" and was originally conceived as the cousin of Martin Manhunter. He appeared in a maxi-series in 1984 by Greg Potter, Gene Colan and Klaus Janson, and was also featured in Grant Morrison's JLA run.
According to CBS, Halford's Jemm is a "powerful alien escapee" who becomes trapped with Hank Henshaw and Alex in the DEO base.
Halford will reportedly debut as Jemm in Supergirl's December 7 episode titled "Human for a Day."