Duke is General Counsel and Vice President of Legal and Governmental Affairs. He specializes in franchise and distribution law, negotiations, alternative dispute resolution techniques and procedures, civil litigation, mergers and acquisitions, proprietary rights, and complex business transactions. Prior to joining The Dwyer Group in March 1994, he was a trial lawyer in Austin, Texas.  

Duke has testified before legislative subcommittees during the examination of possible franchise legislation, he has been a speaker at numerous franchising events, his articles have been published in The Franchise Law Journal, Franchising World, and International Franchising, he has successfully completed the program of negotiation at Harvard Law School, he was awarded the Certified Franchise Executive designation from the International Franchise Association, he was recognized as one of the "Top 50 In-House Attorneys in the State of Texas" by Texas Lawyer Magazine, and he is currently serving a three year term on the State Bar of Texas District 08B Grievance Committee.

He received his Bachelor of Arts, with majors in Political Science and Sociology, from Trinity University, where he was an Academic All-American and four year starter at running back for the Trinity Tigers. He has also earned a Master of Business Administration from the University of Dallas College of Business and a Doctor of Jurisprudence from Thurgood Marshall School of Law.