Lois Lerner, the person who heads the Internal Revenue Service's office for handling tax-exemption applications, refused to testify beyond a opening statement at a congressional hearing today. Appearing before the House Committee on Oversight and Government Reform on the scandal involving IRS handling of exemption requests from politically conservative groups, Lerner said she had done nothing wrong. "I have not broken any laws. I have not violated any IRS rules or regulations," she said. However, on advice of counsel, Lerner exercised her rights under the Fifth Amendment and would not accept questions or provide any additional testimony.