LAS VEGAS - An animal-rights group has filed a federal lawsuit accusing the U.S. Department of Agriculture of improperly withholding information gathered during its investigation into the near-fatal tiger attack on illusionist Roy Horn. People for the Ethical Treatment of Animals is challenging the USDA's decision to withhold affidavits of the agency's employees and witnesses collected while it investigated alleged violations of the Animal Welfare Act and other laws. The USDA said disclosing the affidavits would violate the witnesses' privacy, according to the complaint, which was filed Wednesday in Washington, D.C. PETA contends the public interest in the use and...