OSHKOSH, Wis. (AP) — A man serving two life terms for killing a Wisconsin couple in a slaying that went unsolved for decades has died in prison, state corrections officials confirmed. Eighty-five-year-old Raymand Vannieuwenhoven was convicted last year of fatally shooting 25-year-old David Schuldes and 24-year-old Ellen Matheys in a Marinette County park in 1976. Cold case investigators determined in 2019 that a DNA sample taken from evidence at the crime scene came the Vannieuwenhoven family. A DNA sample from Vannieuwenhoven himself — obtained from a licked envelope for a survey on police performance that he filled out — matched the sample from the scene, according to the criminal complaint. Corrections officials say Vannieuwenhoven died June 17 at a prison in Oshkosh.