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.

Attorney Mark Geragos said that because of his medical condition, Menendez should be granted a furlough to help prepare for an upcoming parole hearing.