John, formerly an owner of Hazel & Thomas, P.C., joined Walsh, Colucci, Lubeley, Emrich & Terpak as Principal-in-Residence in the Manassas Office in 1999. His practice focuses upon obtaining land use approvals for landowners and otherwise obtaining governmental permits from state and local governments, through administrative and judicial processes. It includes extensive representation of local governments in land use, litigation, boundary adjustment and other municipal matters. He is an experienced litigator in state and federal courts in a broad range of complex matters, and is experienced in environmental matters such as wetlands, Chesapeake Bay Preservation areas, historic preservation law, legislative affairs and lobbying. He has extensive experience in local and state government administration.

A 1968 graduate of Louisiana State University in Baton Rouge, Louisiana, with a degree in Political Science and History, he served as a United States Army Infantry Officer in Vietnam from 1970 to 1971. He is a 1974 graduate of the University of Virginia Law School.

Upon graduation, John joined the United States Department of Justice in its Honors Program, where he worked for the Office of Policy and Planning, doing policy analyses for the Attorney General. He was assigned to the White House staff under President Gerald Ford, and served as the third-ranking official of the President's Vietnam Era Clemency Program. He returned to the Justice Department specializing in criminal appeals, and argued numerous cases in federal Circuit Courts throughout the United States.

In 1977, John became Deputy County Attorney for Prince William County, Virginia, and in 1982 he became County Attorney. In both positions he was responsible for advising the Board of County Supervisors and Planning Commission with respect to all land use matters appearing before the Board. He served as the President of the Prince William County Bar Association in 1987-88, and the same year was the President of the Local Government Attorneys of Virginia, an organization with which he remains active. He teaches extensively in planning and zoning, and local government law generally. Since going into private practice he has represented numerous clients in land use matters before the Board in Prince William, and other Virginia jurisdictions. He also represents several localities primarily in connection with land use litigation matters. Among representative projects that he has guided to successful completion in Prince William are Nissan Pavilion at Stone Ridge, a 1.4 million square foot mall for the Lerner Companies, an extensive development project for the Assemblies of God, and Bristow Golf Course. He has written extensively in the area of land use, and is the author of the principal Virginia text on Planning and Zoning in the Commonwealth.

John is a member of the Boards of Directors of the Alliance for the Revitalization of the Courthouse (ARCH), the Prince William County Bar Association, and the Northern Virginia Transportation Alliance, and is active in many community events and organizations.