Four relatives are charged with employing at least 18 undocumented workers at their suburban Chicago sheet-metal company.
The case announced Friday is a rare instance of federal authorities targeting executives over undocumented staff.
Charging documents say an audit found half the 67 employees at Streamwood's KSO MetalFab had fraudulent documents.
Those charged are 81-year-old Dora Kuzelka, 56-year-old Kari Kuzelka, 62-year-old Kenneth Kuzelka and 58-year-old Keith Kuzelka.
The complaint says MetalFab officially confirmed in 2017 it fired the ineligible worker after an immigration agency audit. But Keith Kuzelka later told agents most had been rehired.
Each defendant is charged with harboring an illegal alien, which carries a maximum five years in prison, and one count of a pattern of hiring illegal aliens, which carries up to six months behind bars.
They'll enter pleas at a later date.