Born in Zamboanga City, in 1946, he took Chemical Engineering in Adamson University, but subsequently left school for a radio career at DZRH.O'Hara joined the Philippine Educational Theater Association (PETA)in 1969, and met his longtime collaborator Lino Brocka. O'Hara wrote two of Brocka's best-known works, "Insiang" (1976), and "Tinimbang Ka Ngunit Kulang" (You Were Weighed and Found Wanting, 1974)-while playing a major performance in "Tinimbang."