MARINETTE, Wis. — An 83-year-old man charged with killing a couple in a northeastern Wisconsin park in 1976 has been found competent to stand trial.

A judge in Marinette County Circuit Court on Wednesday found that Raymand Vannieuwenhoven is able to understand the court proceedings and assist in his own defense.

Vannieuwenhoven was arrested and charged last year in the long-unsolved fatal shootings of David Schuldes, 25, and Ellen Matheys, 24, in McClintock Park in Silver Cliff, about 200 miles (320 kilometers) north of Milwaukee.

In March, Judge James Morrison ruled that Vannieuwenhoven did not understand the proceedings and could not assist in his own defense. The judge ordered him to undergo inpatient treatment at Mendota Mental Health Institute in Madison.

For decades, the widower and father of five children lived quietly among the 800 residents of Lakewood, a northeastern Wisconsin town surrounded by forests and small lakes.

Investigators didn't have any major leads until 2018, when a DNA lab in Virginia identified the genealogical background of the suspect. Investigators said tests of Vannieuwenhoven's DNA from a licked envelope matched DNA collected at the crime scene.

Morrison has also reinstated a $1 million cash bond, WLUK-TV reported. A trial is scheduled to begin July 29.