According to an FBI search warrant obtained by the Tribune last year, a bookkeeper for 350Green told authorities that Mason and Gerzanych would ask the employee to submit copies of checks to the city of Chicago as evidence that payment had been made to subcontractors. The city would then reimburse 350Green the money. The problem, according to the search warrant, was that Mason and Gerzanych then instructed the bookkeeper not to mail the checks to the subcontractors.