January 2016 capture, was associated with the Fast and Furious operation. The Justice Department confirmed that the .50-caliber rifle was bought in July 2010 in a straw purchase by someone not known to the ATF at the time, and stated the weapon was not associated with any other crime. In a letter to Congressional leaders, Assistant Attorney General Peter Kadzik, head of the Justice Department's legislative affairs office, wrote, "ATF and the department deeply regret that firearms associated with Operation Fast and Furious have been used by criminals in the commission of violent crimes, particularly crimes resulting in the deaths of civilians and law enforcement officials." Investigations and fallout In the U.S. Congress, Representative Darrell Issa (R–CA–49), chairman of the House Committee on Oversight and Government Reform, and Senator Chuck Grassley (R–IA), ranking member of the Senate Judiciary Committee, led investigations of gunwalking operations. There were investigations by the United States Department of Justice Office of the Inspector General and others. 2011 On January 27, 2011, Grassley wrote a letter to ATF Acting Director Kenneth E. Melson requesting information about the ATF-sanctioned sale of hundreds of firearms to straw purchasers. The letter mentioned a number of allegations that walked guns were used in the fight that killed Border Patrol Agent Brian Terry. A second letter from Grassley on January 31 accused the ATF of targeting whistleblowers. On February 4, 2011, after review and comment from dozens of officials in the Justice Department Criminal Division, the Office of the Deputy Attorney General, the U.S. Attorney's Office in Phoenix, and ATF Headquarters, Assistant Attorney General Ronald Weich sent a response to Grassley regarding his two letters. Weich said claims "...that (the) ATF ‘sanctioned’ or otherwise knowingly allowed the sale of assault weapons to a straw purchaser who then transported them to Mexico [are] false. ATF makes every effort to interdict weapons that have been purchased illegally and prevent their transportation to Mexico.” On February 28, Attorney General Eric Holder requested that the Department of Justice's Inspector General begin an investigation of Fast and Furious. On March 22, 2011, President Barack Obama appeared on Univision and spoke about the gunwalking controversy. He said that neither he nor Attorney General Holder authorized Fast and Furious. He also stated, "There may be a situation here in which a serious mistake was made, and if that's the case then we'll find out and we'll hold somebody