The U.S. Park Service is conducting a mock trial to solve a Civil War mystery.

The question: is a soldier buried in Poplar Grove National Cemetery a Confederate or a Union soldier?

The unusual "trial" was under way Wednesday at Dinwiddie County Courthouse.

The headstone on the gravemarker identifies the remains as Union Sergeant J. Richie of New York.

But the Park Service said it is prepared to replace the stone if a panel of experts concludes the remains are those of Confederate Sergeant Ivy Ritchie of Albemarle, North Carolina.

The possible case of mistaken identity was raised in the book "Battles of Appomattox Station and Appomattox Court House, April 8-9 1865."

Author Chris Calkins works as chief interpreter for the Petersburg National Battlefield.