WAUKESHA, Wis. (AP) Authorities in Wisconsin say an inmate somehow armed himself with a knife and threatened a sheriff's deputy before the officer shot and wounded him.

The Waukesha County sheriff's department says Steven P. Lettenberger, 43, was at the hospital for treatment Friday afternoon. Authorities say he tried to attack the deputy who was guarding him.

The officer then shot Lettenberger, who had been in custody for endangering safety and carrying a concealed weapon. The deputy was not injured.

Lettenberger was in critical condition Friday. The hospital said Saturday it had no listing for him, perhaps because his information had been rendered confidential.

Lettenberger's attorney did not immediately return a call seeking comment.