Grand Central, Penn Station, Radio City Music Hall -- for almost two decades, no place was safe from the man who signed his anonymous letters "FP" and left his lethal devices in phone booths, storage lockers, even tucked into the plush seats of movie theaters. His victims were left cruelly maimed. Tabloids called him "the greatest individual menace New York City ever faced." In desperation, Police Captain Howard Finney sought the help of a little...