Allen's practice is focused primarily on legal issues involving real estate transactions, construction, environmental law, litigation, land use and zoning.

Allen (often known by the initials A.T.) has more than 40 years of experience in the public and private sectors including time spent serving as the Chief Deputy Prosecuting Attorney for the Environmental and Land Use Section of Thurston County, Washington, and as a Washington Assistant Attorney General for the Ecology Division, the Northwest Compact for Radioactive Waste and the Puget Sound Authority. Additionally Allen has served as a registered lobbyist in Washington and has assisted clients in the legislative process in Olympia.

He previously served as an adjunct professor of real estate law at South Puget Sound Community College and has taught environmental law at Seattle University School of Law.

Allen is also an active member of the community. Among his many public service accolades, he successfully chaired the Thurston County United Way Campaign from 2002 to 2005 and served as president of both the Olympia Rotary Club and the Olympia-Thurston County Chamber of Commerce. He was elected twice to the Olympia School Board, and is President of the Board of the Dishman Hills Conservancy. Allen further serves as a member of the Board of Directors of the Spokane Rotary Club 21.

A.T. is married to Suzy Dix, a horse farmer and realtor at Windermere Manito in Spokane. He has three married adult children and two granddaughters all living in Seattle. He is an avid hiker, skier, mountain climber and kayaker and has climbed Mt. Rainier five times, the other Cascade volcanoes at least once, and many other peaks in the Pacific Northwest. 

A.T. is a fourth generation Spokanite with two of his great grandfathers having immigrated to Spokane Falls in the late 19th Century. His father was an Air Force pilot in WW2 and Korea and fought the Cold War at the Pentagon at the end of his 30 years of service. His mother was a social worker who assisted the mentally disabled. His parents retired to Hawaii and are interred at the National Memorial Cemetery of the Pacific in Hawaii.