NYC Tax Fraud Defense Lawyers explain the intricacies of Tax Fraud Investigations and what to do if you receive a letter from the investigators. br br In New York, investigations regarding tax evasion and fraud are started by the Department of Taxation and Finance and the Internal Revenue Service (IRS). If you receive a letter from their units, you should follow these steps: br br 1) Do not engage in conversations with the investigators; br 2) Call a tax fraud criminal defense attorney to request legal representation.