(Somerset, WI)  —  The state of mind of the accused killer in the Apple River stabbing case is at issue.  Fifty-two-year-old Prior Lake man Nicolae Miu says he acted in self-defense on July 30th when he stabbed Stillwater teen Isaac Schuman to death and wounded four others.  The stabbings happened during a confrontation among tubers on the river.  The victims say Miu attacked them first and drew a knife on the unarmed young people.  At least two videos taken of the encounter have been turned over to authorities.