Cameron Ray, 20, was killed in a drive-by shooting March 18 following a fight outside a bar.
Joseph, whose rapper pseudonym is “YKDV Bossman Fat,” has admitted to Cowboys’ officials he was at the scene but was not involved in the shooting, according to Hill.
The team declined comment.
Police released surveillance video to KDFW-TV that appears to show Joseph, wearing a YKDV necklace, among the group of people who fought with Ray and his friends earlier that night.
The Cowboys made Joseph a second-round choice last season, and he played 164 defensive snaps and 142 on special teams in 10 games with two starts. He totaled 16 tackles and two pass breakups.