An eyewitness is muzzled. A leaked report contradicts the official version of the crime. A body is buried before an autopsy can be conducted. A crime scene is hastily cleansed of evidence. What may sound like a standard plot from pulp fiction is playing itself out in Pakistan, where it is widely believed that an active effort to cover up the truth behind the assassination of former prime minister Benazir Bhutto is under way.... Ishtiaq Hussain Shah, the Deputy Superintendent of Police who was alongside Ms. Bhutto's vehicle and gave an account of the assassination to a local newspaper from...