Investigators say, from 2005 to 2011, 53-year-old Mark McDonald, of Wheaton, and 49-year-old David Tepper, of River Forest, billed the agency for equipment and services that were never delivered and stole more than $100,000 that way.
A third man, 37-year-old Arif Mahmood, of Glendale Heights, a former contractor with the forest preserve, is accused of helping.
Mahmood is charged with stealing more than $10,000.
