Former Jenkens & Gilchrist partner Paul Daugerdas was sentenced to 15 years in prison Wednesday for being the architect of the largest tax shelter fraud in U.S. history.

Southern District Judge William Pauley (See Profie) said the Chicago lawyer was “in a class by himself—he was at the apex of tax shelter fraud racketeers” as he built a practice that cost the government $1.6 billion in tax revenues through opinion letters used by the wealthy to shelter billions.