Senior Justice Department officials were aware that ATF agents allowed firearms to be “walked” into Mexico, according to a series of emails last year in which they discussed two undercover operations on the Southwest border, including the failed Fast and Furious program.

In the emails that the department turned over to congressional investigators, Justice Department officials last October discussed both the Fast and Furious gun-trafficking surveillance operation in Phoenix and a separate investigation from 2006 and 2007 called Operation Wide Receiver. In Wide Receiver, which took place in Tucson, firearms also were acquired by illegal straw purchasers and lost in Mexico, the emails say.