Saying the Illinois courts are free to determine for themselves whether a state law violates the U.S. Constitution, a federal judge has turned aside a defendant’s bid to block state prosecutors from pursuing charges of carrying a concealed gun. In a written opinion, U.S. District Judge Virginia M. Kendall held that the federal courts would be improperly interfering in the business of the state courts if she halted Peter Harper’s state prosecution. Kendall conceded that a federal appeals court in an …