CHICAGO – The nephew of former Chicago Mayor Richard M. Daley pleaded not guilty Monday to involuntary manslaughter in the 2004 death of a suburban man whose family suspects a police cover-up in the initial investigation into the fatal fight.

The case hit a potential snag just minutes after 38-year-old Richard Vanecko's arraignment began when the assigned judge told attorneys he worked as a prosecutor under the ex-mayor, telling both sides they can decide if they want him switched out for another judge.

A somber-looking Vanecko walked by dozens of TV cameras and reporters for his arraignment at a Cook County courthouse eight years after a fight outside a Chicago bar led to the death of David Koschman, who was 21 at the time.