The documents are about an employee who allegedly received an illegal property tax break.
This sets up a new legal battle with Berrios.
Last summer the county's ethics board recommended Berrios fire the son and daughter he hired them to work for him and fined him $10,000. He's refused to pay, saying ethics rules don't apply to him.
Cook County Board President Toni Preckwinkle is now seeking to appoint a special prosecutor to recover the fine.
