CHICAGO (AP) — A federal lawsuit alleges two former prosecutors conspired with a Chicago police sergeant and others to fabricate evidence that led to a wrongful murder conviction.

With the lawsuit filed Monday, attorney Jennifer Bonjean said she is seeking $60 million in damages for Armando Serrano. He and co-defendant Jose Montanez were released last summer after more than two decades in prison when prosecutors dropped charges.

The lawsuit alleges former Detective Reynaldo Guevara and then-assistant state’s attorneys Matthew Coghlan and John Dillon worked together to pressure a key witness into pinning the 1993 murder of Rodrigo Vargas on Serrano.

Coghlan, now a judge, couldn’t be reached for comment. Dillon declined to comment.

Guevara has come under fire over allegations he bullied witnesses and framed innocent people in dozens of cases. He’s invoked his right against self-incrimination when questioned about the accusations.