The Devil's Teardrop [antikvár]

At 9 am on 31st December a man gets onto the packed escalator of a metro station and fires a silenced machine gun through a paper bag. He escapes without being spotted in the confusion caused by dozens of killed and injured people. A note is delivered to the mayor of Washington, D.C., demanding $20 million, or the writer will instruct the gunman to strike again, at 4.00, 8.00 and midnight. The mayor decides to pay up. But then a man is killed in a hit and run accident - his fingerprints match the prints on the note. With the brains behind the operation dead, there's no way of stopping the gunman killing again, and again, and again...