Professor Dehn joined the Loyola faculty in the fall of 2013 after serving over 23 years in the U.S. Army.  Upon graduating from the United States Military Academy at West Point, Professor Dehn served at Fort Bragg, North Carolina as an airborne artillery and logistics officer with certifications as a parachutist, jumpmaster and aerial delivery officer.  After a successful early career that included participation in Hurricane Andrew relief and the 1994 Haiti operations, Professor Dehn was selected to attend law school at government expense.

After graduating from law school with highest honors, Professor Dehn served for over fifteen additional years as an Army judge advocate in positions ranging from chief prosecutor for a military installation to faculty member at West Point.  He also served as a military magistrate, detainee abuse prosecutor and in several other capacities. He earned two Master of Laws (LL.M.) degrees, one from Columbia Law School where he was a James Kent Scholar.

While at West Point, Professor Dehn taught courses in international, constitutional and military (including criminal) law, served as an honors thesis advisor, coordinated legal training for all academy programs, coached the Jean-Pictet International Humanitarian Law Competition team, and lectured in courses on the military profession.  In 2010, he was appointed the Distinguished Visiting Lecturer in American Public Policy and Practice at Hamilton College and taught a seminar on war powers.