He served as the Chief Pathologist at the Abu Kabir Institute of Forensic Medicine between 1988 and possibly as late as 2005.
Hiss has also served as part of the faculty for the Terrorism and Medicine Program at the Institute for Counter-Terrorism (ICT) at IDC Herzliya and in the Department of Pathology for the Sackler Faculty of Medicine at Tel Aviv University.As director of the Institute at Abu Kabir, the only place in Israel authorized to conduct autopsies in cases of unnatural death, Hiss conducted the autopsies of and authored the pathology reports for notable figures, including Yitzhak Rabin and Rachel Corrie, among others.
His position as director was a subject of controversy.
He was dismissed from this position after the legal system took up some of the charges against him.
Investigations of the newspaper Al-Ahram, revealed that Hiss had removed organs, bones and other tissues from corpses, against the expressed wishes of family, and had sold many of the organs he removed to medical institutions and universities.
He remained the chief pathologist of the Institute and regained his position as director before being dismissed by the Deputy Health Minister Yaakov Litzman on Oct 15 2012.