The Vermont State Police have announced that three troopers may have potentially violated federal law by allegedly participating in a scheme to make fake COVID-19 vaccination cards. Investigators with the U.S. Attorney’s Office in Vermont and the FBI have opened a criminal probe into the men, who are each suspected of having “varying roles” in the alleged fraud. All three men have resigned from the force. Shawn Sommers and Raymond Witkowski, who handed in their badges on Aug. 10, have been with the force since 2016. The third, David Pfindel, who submitted his resignation on Sept. 3 after an investigation was opened by the Department of Public Safety, has been a trooper since 2014.

A spokesperson did not say why the troopers were allegedly making the cards or who the men might have been providing the cards to, VTDigger reported. But the director of the Vermont State Police, Colonel Matthew T. Birmingham, did express embarrassment. “The accusations in this case involve an extraordinary level of misconduct—a criminal violation of the law,” he said, “and I could not be more upset and disappointed.”