 In January, Patrick Cunningham, who was the criminal division chief at the Phoenix office of the U.S. Attorney's Office for the District of Arizona and has since resigned, asserted his innocence and his constitutional right against self-incrimination to avoid testifying.Cunningham worked directly under Burke during Fast and Furious.He was subpoenaed because of the role he might have played in the operation, and in the letter sent from the DOJ to Senator Grassley in February 2011 that claimed the ATF did not allow weapons to be trafficked to Mexico.