WASHINGTON - CBS News has obtained secretly recorded conversations that raise questions as to whether some evidence is being withheld in the murder of a Border Patrol agent. (Scroll down to listen to the audio) The tapes were recorded approximately mid-March 2011 by the primary gun dealer cooperating with ATF in its "Fast and Furious" operation: Andre Howard, owner of Lone Wolf Trading Company (external - login to view)in Glendale, Arizona. He's talking with the lead case ATF case agent Hope MacAllister. The tapes have been turned over to Congressional investigators and the Inspector General.

As CBS News first reported (external - login to view)last February, the Bureau of Alcohol, Tobacco, Firearms and Explosives allegedly allowed thousands of weapons to "walk" onto the streets without interdiction into the hands of suspected traffickers for Mexican drug cartels in its operation "Fast and Furious."
The conversations refer to a third weapon recovered at the murder scene of Border Patrol Agent Brian Terry.

Secret recordings raise new questions in ATF 'Gunwalker' operation - CBS News Investigates - CBS News (external - login to view)