He has led the defense of federal and state criminal tax offenses at the investigatory, grand jury, and trial levels in cases involving tax evasion, willful failure to file, conspiracy to commit tax evasion, bribery of a federal agent, evasion of state sales tax, and bankruptcy fraud. He has extensive experience in all aspects of civil tax litigation including that conducted in the U.S. Tax Court, U.S. District Court, and the U.S. Federal Court of Claims. Kirk is designated as a Certified Specialist in Tax Law by the Arizona Board of Legal Specialization and has been named in the Southwest Super Lawyers list for 2009, 2010, 2011, and 2012..