He found one of Stalin's mass graves. Now he's in jail.

Mr. Dmitriev, meanwhile, has been sitting in a pretrial detention center in Petrozavodsk, the capital of Karelia. Late last month, a municipal court — sealed off to visitors because of the coronavirus — extended his detention for another three months.

A few days later, the curator of a museum near Sandarmokh, who had supported Mr. Dmitriev’s work and had also been jailed on pedophilia charges, died in a prison hospital from an unspecified illness.

Ms. Klodt said she had no doubt about her father’s innocence and blamed his travails on his stubborn insistence that all victims be remembered, not just those killed by foreigners. Sitting on a bench near a tree pinned with an American flag commemorating a man from San Francisco executed in Stalin’s Great Terror, she pointed with disgust at a snow-covered hole dug by the Military Historical Society as part of its search for Russians killed by Finland.

“I am so tired of this circus,” she said. “I don’t understand what they are trying to prove.”