Rape charges have been added against a convicted sex offender who allegedly held his girlfriend hostage for several days in their RV, during which time he beat and threatened to shoot her.The alleged rapist, Mark Kevin Smith, 38, of Clarksville was originally charged with aggravated kidnapping, possession of a firearm by a convicted felon, violation of the sexual offender registry and aggravated assault. However, after hearing the case against him, the grand jury not only indicted him on those charges but also added three counts of rape for acts perpetrated against his girlfriend while she was held hostage in the small camper.The victim said she was viciously beaten by Smith and was then not permitted to leave the RV.“He slammed her head against her truck,” said sheriff’s investigator Jason Rowland of the initial attack. “She still had numerous bruises from the attack visible at the time of this report.”The investigator said the suspect was brandishing a pistol, terrorizing the victim during the time she was held hostage.“Mr. Smith was armed with a pistol and told the victim, on more than one occasion, that he would kill her,” Rowland said of the days she was kept inside the small RV.An inspection of Smith’s record prior to his arrest revealed he is a convicted sex offender, convicted of sexual assault in 2007.