mistaken identity? >> clearly all evidence indicates that this was a case of mistaken identity based on the tactical intelligence i've seen surrounding the case. >> the most likely scenario is david and tiffany hartley had wandered into a drug war and were mistaken as the enemy. zapata county sheriff gonzalez believes the hartleys had not only wandered into a war but had arrived on the mexican side of falcon lake at the exact moment a cartel was about to move a large amount of marijuana. up on a bluff, the spotters, his sources told him, caught the first glimpse of a possible glitch in the drug deal. >> that area is an area that's notorious for crossing or storing of thousands of pounds of marijuana. we've known that for a long