He could have received a ten-year sentence but he co-operated with the prosecutors in their cases against two other former partners in the firm, Paul Daugerdas (once head of the Chicago office) and Donna Guerin. They have been sentenced to 15 years and eight years, respectively. 

Biggest US tax fraud

The prosecution was described by federal prosecutors as the biggest tax fraud to have been prosecuted in the US. The prosecutors said that Mr Daugerdas arranged a system in which false tax shelter schemes were marketed to some 1,000 well-off investors in the decade to 2004. In 2001, Jenkens & Gilchrist had 600 lawyers but, hit by the tax shelter scandal, it finally stopped operations in 2007. Source: ABA