The former veteran patrolman has been indicted on rape, kidnapping and other sex charges in connection with an alleged assault on a 23-year-old woman.
Prosecutors say last month, he picked up the woman, who was intoxicated, and drove her to a side street.
McCombs is charged with assaulting her while fellow officer Christopher Dillenbeck did not stop him.
Dillenbeck was not charged.
Assistant Cuyahoga County Prosecutor, David Zimmerman, said "Officer Dillenbeck has given us a full statement. He is cooperating with us. From our information we have it was Officer McCombs that's the perpetrator here."
Added Parma Mayor, Dean DePiero, "I think the silver lining is there was alleged misconduct and it was brought forth from our police department. It wasn't a complaint. We followed up on a rumor."
Both patrolmen were fired last week.
If convicted McCombs could face more than 50 years in prison.