The 2012 convictions stemmed from attacks in which Amish attacked other Amish, cutting their beards and hair.
Federal prosecutors had argued that the attacks violated a 2009 federal hate crimes law because religious differences were a motivating factor.
But in its ruling, the 6th U.S. Circuit Court of Appeals said religion had to be the central triggering factor in the attacks.
"The 6th Circuit noted that the evidence shows all kinds of motivating factors," said Wendi Overmyer, a public defender who argued to overturn the convictions. "There’s personal reasons, there’s power struggles, there’s some religious disputes, there’s this whole history between the perpetrators and the victims in this case."
The U.S. Attorney for the Northern District of Ohio, Steven Dettelbach, who prosecuted the case, said in a statement his office disagreed with the ruling and was considering options, including retrying the case.
Followers of Amish leader Sam Mullet Sr. cut the beards and hair of nine others in eastern Ohio who disagreed with Mullet’s unusually strict leadership. Hair is a sign of religious piety for the Amish.
Overmyer says this is the first test of the hate crimes law in a case involving a religious dispute.