A federal judge has agreed to step down from a potential class-action lawsuit over conditions at an Idaho prison at the request of its operator, Corrections Corp. of America.  Chief U.S. District Judge B. Lynn Winmill has been handling the lawsuit brought by inmates at the Idaho Correctional Center. He announced Tuesday that he was recusing himself after CCA attorneys claimed his staff improperly approached an ACLU attorney about taking the case. Winmill stressed that there was no improper conduct, and the staffer that contacted the attorney was simply doing her job as a pro bono coordinator — a court worker who finds attorneys to take cases for no charge. But he said he wouldn't risk even the suggestion of impropriety, and so would step down. The inmates claim the Boise-area prison is so violent that it's called "Gladiator School" and that the guards use inmate-on-inmate violence as a management tool and then deny injured inmates adequate medical care to cover up the violence.