Now Madriani is faced with daunting ballistics evidence: a so-called "double tap"-two bullet wounds tightly grouped in the victim's head, shots that could have been made only by a crack marksman. Paul's client, Emiliano Ruiz, is an enigma€"a career soldier who refuses to discuss his past though it is clear that he is a battle-tested pro. Ruiz is accused of killing a beautiful businesswoman and guru of a high-tech software empire catering to the military. A key to the case: the murder weapon is one used solely in special operations, where the "double tap" has become the signature of the most skilled assassins.