(Excerpt) Gunwalking is a controversial investigative tactic in which police allow suspects to traffic guns without stopping them in order to see where they end up. Documents just released this afternoon show the head of the Justice Department's criminal division, Lanny A. Breuer, learned about the tactic of ATF gunwalking as early as April of last year. In a memo, Breuer's deputy wrote him that, in a case called "Wide Receiver" started under the Bush Administration, "ATF let a bunch of guns walk" in an effort to catch the big fish of Mexican drug cartels and said the gunwalking case...