CHICAGO (CBS) — A former Cook County correctional officer has filed a lawsuit against Sheriff Tom Dart, alleging he was “illegally fired” by an “unlawful merit board.”

“I wanted to fight. I wanted to stand up for what I believe is right,” said Joseph Acevedo, who was fired in 2015, after 16 years as a correctional officer.

Attorney Dana Kurtz said her office has filed a class-action lawsuit, claiming the Cook County Sheriff’s Merit Board, which decided his fate, was not lawfully seated – specifically, board member John Rosales.

“The court found that Sheriff Dart had made an illegal appointment of Rosales, who’d been political contributions to Sheriff Dart for years. That decision includes and can include – and that’s the purpose of the lawsuit – all of the Cook County Sheriff’s employees who were illegally fired and disciplined by this illegal board for which John Rosales sat on,” she said.

Kurtz estimated some 100 firings, promotions, and suspensions could now be in question.

The sheriff’s office said its appealing the court decision regarding Rosales’ appointment.