A former minister was acquitted on Friday of murder in the 1975 killing of Gretchen Harrington, who was 8 years old when she was abducted on her way to a Bible camp outside Philadelphia and beaten to death.

It took jurors about an hour to reach a verdict in the case of the former minister, David Zandstra, 84, whose lawyers had vigorously argued during the four-day trial that their client had been coerced into confessing to a crime that had confounded investigators for decades.

In addition to being cleared on counts of first-, second- and third-degree murder, Mr. Zandstra was also found not guilty on all other charges, including criminal homicide, kidnapping of a minor and possessing an instrument of crime.

Mr. Zandstra had served as a pastor at the Trinity Chapel Christian Reformed Church in Broomall, Pa., which is where Gretchen was headed on morning of Aug. 15, 1975, when she disappeared. The church was less than half a mile down the road from her home.

A hiker discovered her remains two months later in Ridley Creek State Park, which is about 25 miles west of Philadelphia in Delaware County, Pa.

In a statement issued after the verdict, Christopher Boggs, one of Mr. Zandstra’s lawyers, said that his client had steadfastly maintained his innocence over the years.