Excerpt from Empire of Sin by Gary Krist, plus links to reviews, author biography & more

The attack—Always on sleeping victims with no apparent choice between men and women, and use of the blade of the weapon as a rule.

Precautions—Complete failure to find fingerprints, together with the fact a pair of rubber gloves was left behind in one case, leads to the belief that the murderer uses rubber gloves to protect himself against identification by the fingerprint method.

Robbery as a Camouflage—In practically every ax murder, while bureaus, safes, and cabinets have been ransacked, little was stolen, and money and valuables in plain sight were left behind. And in numerous instances of "panel burglaries," the work of the intruder has been so incomplete as to leave strong doubt whether robbery was the real motive.

Mooney did acknowledge that each assault and break-in could conceivably be a separate, unrelated incident. He also admitted that they all might be part of a systematic campaign of revenge or terrorism by the Mafia or Black Hand. But he remained convinced that the culprit in all or most of the incidents was a "solo maniac"—"a diabolical, bloodthirsty fiend, cunning and shrewd," as the Times-Picayune described him, "a slinking agent of the devil at 3 AM."

Then, on Sunday, March 16, the city received a kind of confirmation of this macabre description. The Times-Picayune reprinted a remarkable document the paper had received in the mail on Friday. It was an open letter to the public purporting to be from the axman himself. Addressed to the newspaper's editor, and written in a hand similar to that of the letters received by Superintendent Mooney from the anonymous criminologist, it began with an attention-getting flourish: "Esteemed Mortal: They have never caught me and they never will. They have never seen me, for I am invisible, even as the ether which surrounds your earth. I am not a human being, but a spirit and a fell demon from hottest hell. I am what you Orleanians and your foolish police called the axman."

The letter went on to ridicule the police for their inept investigation of his crimes. The department's antics had been so "utterly stupid," in fact, that they had amused not only him, but also "His Satanic Majesty" and the recently deceased emperor of Austria, Franz Joseph, among other denizens of hell. "Undoubtedly you Orleanians think of me as a most horrible murderer, which I am," he continued, "but I could be much worse if I wanted to. If I wished to, I could pay a visit to your city every night. At will I could slay thousands of your best citizens, for I am in close relationship with the Angel of Death."

The letter writer followed this with a threat, specifying the time of his next appearance: "Now, to be exact, at 12:15 o'clock (earthly time) on next Tuesday night, I am going to pass over New Orleans."

But those in fear of their lives had one way to protect themselves:

"I am very fond of jazz," he wrote, "and I swear by all the devils in the nether regions that every person shall be spared in whose house a jazz band is in full swing at the time I just mentioned. If everyone has a jazz band going, well, then so much the better for the people. One thing is certain, and that is [that] some of those persons who do not jazz it on Tuesday night (if there be any) will get the ax." The letter was signed, simply: "The Axman."

The sensation created by this letter—particularly in the poorer ethnic neighborhoods that had been hardest hit by the ax crimes—can only be imagined. Certainly many, if not most, people in the city must have doubted the authenticity of the document. There was something too slick—too ironic and knowing—about the entire exercise to be fully convincing as the ramblings of a crazed maniac. But for a populace traumatized by a bizarre and brutal crime wave, the letter was a shock, hoax or no hoax. After all, something was stalking the streets at night with malicious intent. And if the way to appease the demon was to cut loose for a night, then New Orleans, starved of music and conviviality by the forces of reform, would cut loose with abandon.

Excerpted from Empire of Sin by Gary Krist. Copyright © 2014 by Gary Krist. Excerpted by permission of Crown, a division of Random House LLC. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.