When 12 bodies were found buried in the garden of a Mexican house, it seemed like a case of drug-linked killings. But the trail led to Washington and a cover-up that went right to the top. David Rose reports from El Paso Janet Padilla's first inkling that something might be wrong came when she phoned her husband at lunchtime. His mobile phone was switched off. On 14 January, 2004, Luis had, as usual, left for work at 6am, and when he did not answer the first call Janet made, after taking the children to school, she assumed he was busy....