NAHA, Okinawa Pref. (Kyodo) Police turned over to prosecutors Monday their case against a U.S. Army staff sergeant who was allegedly involved in a fatal hit-and-run in Yomitan, Okinawa.

The case against 27-year-old Clyde Gunn alleges negligence while driving resulting in death, the prefectural police said.

Japanese investigative authorities are considering adding a separate hit-and-run charge, but their efforts have been stalled by Gunn's refusal to undergo direct questioning, citing human rights concerns, investigative sources said.

The staff sergeant at the Torii Communications Station in the village of Yomitan has effectively admitted his involvement in the Nov. 7 incident that left a 66-year-old man dead, according to his lawyer. He remains in U.S. custody.