Consular Post Appearances Worldwide. Robert G. Heiserman P.C. practices only immigration in his Denver, CO office. He has over 35 years’ experience. Clients of his firm are primarily employers seeking work authorization for international employees. He also represents individuals seeking visas and green cards. Services include immigration law services and consular post visa appearances worldwide: • Employment authorization for personal or business • Family visas • I-9 compliance review • Naturalization • Consular law • M&A due diligence Robert G. Heiserman has also been an adjunct professor of law at the University of Denver College of Law. He is the founder of the Colorado chapter of the American Immigration Lawyers Association. For additional information please call Robert G. Heiserman P.C. for an appointment today.