GRAND JUNCTION, Colo. -- A 91-year-old man will face at least three charges after a nursing home nurse accused him of trying to sexually assault her.

Ralph Allen Ridenour, of Palisade, Colo, has been charged with attempted sexual assault through the use of force, attempted sexual contact through use of force, and false imprisonment.

He was arrested on Oct. 21 after a nurse at Palisade Living Center told police that Ridenour grabbed her by the shirt, pulled her pants down and threatened to rape her when she tried to give him his medicine.

Ridenour was later transferred to the Veterans Affairs Medical Center for treatment of a blood clot in his leg.

Public Defender Ryan Esplin said his client's mental condition would be a key question in the case.

Ridenour has another court hearing scheduled for Jan. 2.

According to the Grand Junction Sentinel, Ridenour is a registered sex offender. He was arrested by the Mesa County Sheriff’s Department on Feb. 2, 2006, on suspicion of two counts of felony sexual assault on a child.