Mr. Lilien received his Juris Doctor from Notre Dame Law School in 1978 and was admitted to the Illinois Bar that same year. He joined the Office of the State Appellate Defender as an Assistant Defender in the Third District Office in October 1978 and worked there until his transfer to the Second District Office in 1988. Mr. Lilien continued to serve as an Assistant Defender until he assumed the Deputy Defender position as of January 1, 2006.
Mr. Lilien is admitted to practice in the Illinois Supreme Court and United States Supreme Court. He is a member of the Board of Directors of the Illinois Institute for Continuing Legal Education and was the general editor for the most recent edition of its publication Defending Illinois Criminal Cases, as well as the 2013 supplement. He has served as an adjunct faculty member co-teaching the appellate advocacy course at the NIU College of Law since the inception of the class and has supervised student externs from the course in both the Second and Third District Offices.