Court proceedings in the sexual assault case against Senior Airman Gabriel Lopez started Monday at Ramstein Air Base, Germany.

Lopez is charged with wrongful sexual content stemming from a December 2007 off-base incident at his residence in which he allegedly performed a sex act on another man without that man’s consent, said Air Force Capt. Gloria Downey. It is unclear whether the alleged victim was asleep or unconscious at the time, she said.

The alleged victim, his wife, DNA experts and people who took the man to the hospital are scheduled to testify.