ATF Chief Reassigned After Troubled Gun Sting – The Justice Department reassigned the head of the Bureau of Alcohol, Tobacco, Firearms and Explosives, and the top federal prosecutor in Arizona resigned as part of a broad shake-up in the wake of a troubled federal antitrafficking operation. Kenneth Melson, acting ATF director since April 2009, is moving to a new post with oversight of forensics in the Justice Department’s Office of Legal Policy, the department said Tuesday. B. Todd Jones, U.S. attorney in Minnesota, will succeed Mr. Melson as interim head of the ATF.