A judge did not overstep her bounds when she barred an expert witness from testifying a Chicago police officer accused of beating a store employee followed departmental policy, a federal appeals court held.The 7th U.S. Circuit Court of Appeals last week affirmed Aldo Brown’s conviction on one count of willfully depriving the employee of his Fourth Amendment right to be free from excessive force in violation of 18 U.S.C. Section 242.The court rejected the argument that U.S. District Judge Virginia M. Kendall erred in …