were using it in a bank holdup." "Then why did they do that?" Stevenson followed Hastings' pointing finger, and saw again the crudely-lettered words, "The Scorpion" burned black into the paint of the trunk lid. "I really don't know," he said. "It wasn't there before the car was stolen?" "Of course not!" Stevenson frowned. "Now, why in the world did they do that?" "I suggest," said Hastings with heavy sarcasm, "you ask them that." Stevenson shook his head. "It wouldn't do any good. They aren't talking about anything. I don't suppose they'll ever tell us." He looked at the trunk lid again. "It's the nuttiest thing," he said thoughtfully.... That was on Wednesday. The Friday afternoon mail delivery to the Daily News brought a crank letter. It was in the crank letter's most obvious form; that is, the address had been clipped, a letter or a word at a time, from a newspaper and glued to the envelope. There was no return address. The letter itself was in the same format. It was brief and to the point: Dear Mr. Editor: The Scorpion has struck. The bank robbers were captured. The Scorpion fights crime. Crooks and robbers are not safe from the avenging Scorpion. WARN YOUR READERS! Sincerely yours, THE SCORPION The warning was duly noted, and the letter filed in the wastebasket. It didn't rate a line in the paper. II The bank robbery occurred in late June. Early in August, a Brooklyn man went berserk. It happened in Canarsie, a section in southeast Brooklyn near Jamaica Bay. This particular area of Canarsie was a residential neighborhood, composed of one and two family houses. The man who went berserk was a Motor Vehicle Bureau clerk named Jerome Higgins. Two days before, he had flunked a Civil Service