Mark Salling allegedly raped a 22-year-old woman ... so claims the alleged victim, and now the L.A. County D.A. is deciding whether to file charges against him.
A woman claims she and Salling entered a room to have intercourse, but she changed her mind and told him no, saying, "I can't do this" -- this according to the police report. She told cops he refused to stop and forced himself on her.
The alleged victim filed a police report in April of this year ... nearly 4 years after the incident. She tells us she knew months earlier the former "Glee" star had been arrested for possessing child ****.
The D.A. is reviewing the case for possible rape charges.