National Football League free agent safety C.J. Spillman has been charged with sexual assault in a September incident at a Dallas-area hotel when he was playing for the Cowboys, officials said on Wednesday.

Spillman, who has played six seasons in the NFL, is suspected of sexual assaulting a woman at the hotel, which is used by the Cowboys, and then traveling with the team the next day to play against the St. Louis Rams, police and prosecutors said.

Spillman, 29, has been under investigation in the case for 10 months, police in the Dallas suburb of Grapevine have said.