Jack Winters owns a small business, offering construction services for Disney. To save money on his bids, he subcontracts all of the painting out to another company called Painters Inc. While balancing QuickBooks from the actual job invoices and receipts, Jack notices a discrepancy. Painters Inc. was issued a check for $14,125, but the job invoice shows that the job was finished for $12,125. Jack contacts Painters Inc, who provides proof that they received payment for $12,125. Besides Jack, only one person had access to the accounting software. You have been called to investigate. 

Write a one-page report detailing the steps Jack needs to take to gather all of the appropriate evidence and protect his company.