An attorney for the Menendez brothers, who were convicted in the infamous 1989 murders of their parents, says Erik is suffering from a "serious" medical condition and should be released from prison immediately.

Erik Menendez, 54, is in the hospital and has been diagnosed with a serious medical condition, his family confirmed to ABC News.

Erik Menendez and his brother, Lyle, have spent more than 35 years prison for killings their parents in 1989 in a case that over the past year has gained renewed public attention following the release of Netflix's "Monsters: The Lyle and Erik Menendez Story" and various documentaries.