Arguing he was entitled to a for-cause dismissal of a juror who had a preconception about a material question of law — and also that the trial judge should have granted his request to expand the jury from eight to 10 so he would have had a chance of getting at least one African-American juror — Kenneth Marshall appealed from a judgment for the defendants in his civil rights case against the city of Chicago and several police officers. Marshall — who had a felony record and was barred from possessing …