An exhibit at Atlanta’s High Museum of Art this fall “will include the first U.S. showing of Beheading the Baptist, a silver relief depicting seven figures at the execution of John. The question is who created the relief. For centuries it has been credited to Florentine sculptor Andrea del Verrocchio, who was Leonardo’s mentor. But Gary Radke, guest curator of the exhibit at the High, believes that two of the figures are the work of Leonardo himself.”