The "sonic device" was a highly lethal weapon employed by the Hands of Blue. It was small enough to be carried in a coat pocket and when activated caused massive internal bleeding and hemorrhaging from every opening (including under finger nails and sweat pores) in the human body. The activated weapon emitted an increasingly high pitched tone; as the tone grew more intense, the injuries sustained by nearby targets became more and more grave. The weapon functioned with a broad area of effect and spared only those who were immune to its effects (those employing the weapon) and those who were too far away. Its use appeared to be to remove all inconvenient potential witnesses.