Samuel Mullet, 66, along with 15 of his male and female followers in Jefferson County are accused of cutting the beards of Amish men.
Defense lawyers said the group also has requested any Amish person called to the witness stand "affirm the truthfulness" of their testimony rather than take an oath, which would be against their religion, The (Cleveland) Plain Dealer reported.
Seven Amish men had their heads and beards shaved in attacks that began last year, which Mullet is accused of orchestrating. The Amish believe their hair and beards hold religious significance, and to shave either is considered degrading.
Among the evidence to be used in the Aug. 27 trial are 8-inch horse mane shears, photographs and hair collected from a home.
Prosecutors say Mullet sought revenge after a group of Amish bishops refused to accept his decision to excommunicate eight families who had left their community because they disagreed with Mullet's leadership.
Mullet also allegedly forced women to have sex with him to learn how to better please their husbands, prosecutors said.