COLUMBIA, S.C. -- A federal grand jury has indicted a 42-year-old man who authorities say held police at bay for 18 hours outside a Conway hospital, blocking the emergency room entrance.

Robert McGowan was indictment Wednesday for being a felon in possession of a firearm and ammunition.

Authorities say McGowan had a .22-caliber rifle and ammunition on Oct. 21 when he drove into the ambulance bay at Conway Medical Center and put the gun to his head.

No one was injured in the standoff. McGowan said he wanted help and was considering suicide. He spent 10 years in prison for shooting a police officer in the hand and had trouble adjusting after his release last December.

McGowan's attorney Bill Nettles said Wednesday he had no comment on the indictment.