of sophisticated surveillance techniques such as federal wiretaps, which would require court orders and interaction from Justice Department officials in Washington, D.C. since federal law requires certain individuals to review evidence and certify the necessity of such techniques. The dealers involved became concerned as months went by and the same individuals they reported to ATF as suspected straw purchasers returned and repeatedly bought identical weapons. As they later told the DOJ OIG, their previous experience was that after they reported a suspected straw to ATF, they did not see the straw again unless subpoenaed to testify against the straw at trial. One cooperating dealer expressed his concerns in a series of emails in April and June 2010 to GS David Voth, who assured the dealer that ATF was monitoring the suspects using a variety of techniques that he could not discuss in detail. The tactic of letting guns walk, rather than interdicting them and arresting the buyers, led to controversy within the ATF. As the case continued, several members of Group VII, including John Dodson and Olindo Casa, became increasingly upset at the tactic of allowing guns to walk. Their standard Project Gunrunner training was to follow the straw purchasers to the hand-off to the cartel buyers, then arrest both parties and seize the guns. But according to Dodson, they watched guns being bought illegally and stashed on a daily basis, while their supervisors, including David Voth and Hope MacAllister, prevented the agents from intervening. However, other accounts of the operation insist that ATF agents were prevented from intervening not by ATF officials, but rather by federal prosecutor Emory Hurley, who stated agents did not have sufficient evidence to arrest suspected straw-buyers. According to some reports, many agents insisted they were prevented from making arrests because prosecutors were unwilling to engage in what could become a potentially contentious political battle over Second Amendment rights during an election year, particularly given the difficult nature of prosecuting straw buyers, and the weak penalties associated with it, even if successful. Instead, prosecutor Hurley instructed ATF agents not to make arrests, but rather continue collecting evidence in order to build a stronger case. One tactic proposed for doing so was a wiretap of suspected straw-buyers, in an attempt to link the suspects to criminal activities taking place on the Mexican side of the border. Between March 20 and July 30, 2010, nine wiretaps were