>> not every weapon seized in mexico has a serial number that would make it traceable. and the u.s.est to trace weapons only extends to weapons that have been in the u.s. market. >>trace: in 2007 and 2008, 29,000 guns were found at scenes of violence in mexico but only 6,000 of those guns were able to be traced. it is true that of the 6,000 that were traceed 90 percent led back to the united states but of the overall number found in mexico, only 17 percent came from the united states so it is important when you talk about the numbers to add the the context. >>shepard: the white house will release the review of the war in afghanistan. so far we have heard it will include examples of what they call "progress." and "serious challenges." we will hear from author and filmmaker and neighbor of osama