Press reports during the height of public panic about the killings mentioned similar murders as early as 1911, but recent researchers have called these reports into question. At least a dozen grisly deaths were attributed to he serial killer in just over a year.
The Axeman was never identified, and the murders remain unsolved.
As the killer's epithet implies, the victims usually were attacked with an axe, which often belonged to the victims themselves. In most cases, a panel on a back door of a home was removed by a chisel, which along with the panel was left on the floor near the door.
The intruder then attacked one or more of the residents with either an axe or straight razor. The crimes were not motivated by robbery, and the perpetrator never removed items from his victims' homes.
The majority of the Axeman's victims were Italian immigrants or Italian-Americans, leading many to believe that the crimes were ethnically motivated. Many media outlets sensationalized this aspect of the crimes, even suggesting Mafia involvement despite lack of evidence.
Some crime analysts have suggested that the killings were related to sex, and that the murderer was perhaps a sadist specifically seeking female victims. Criminologists hypothesize that the Axeman killed male victims only when they obstructed his attempts to murder women, supported by cases in which the woman of the household was murdered but not the man.
A less plausible theory is that the killer committed the murders in an attempt to promote jazz music, suggested by a letter attributed to the killer in which he stated that he would spare the lives of those who played jazz in their homes.
The Axeman was not caught or identified, and his crime spree stopped as mysteriously as it had started. The murderer's identity remains unknown to this day, although various possible identifications of varying plausibility have been proposed.
On March 13, 1919, a letter purporting to be from the Axeman was published in newspapers saying that he would kill again at 15 minutes past midnight on the night of March 19, but would spare the occupants of any place where a jazz band was playing.
That night all of New Orleans' dance halls were filled to capacity, and professional and amateur bands played jazz at parties at hundreds of houses around town. There were no murders that night.
According to Wikipedia, crime writer Colin Wilson speculates the Axeman could have been Joseph Momfre, a man shot to death in Los Angeles in December 1920 by the widow of Mike Pepitone, the Axeman's last known victim.
Wilson's theory has been widely repeated in other true crime books and websites. However, true crime writer Michael Newton searched New Orleans and Los Angeles public, police and court records as well as newspaper archives, and failed to find any evidence of a man with the name "Joseph Momfre" (or a similar name) having been assaulted or killed in Los Angeles.
Newton was also not able to find any information that Mrs. Pepitone (identified in some sources as Esther Albano, and in others simply as a "woman who claimed to be Pepitone's widow") was arrested, tried or convicted for such a crime, or indeed had been in California.
Newton notes that "Momfre" was not an unusual surname in New Orleans at the time of the crimes.
It appears that there actually may have been an individual named Joseph Momfre or Mumfre in New Orleans who had a criminal history, and who may have been connected with organized crime; however, local records for the period are not extensive enough to allow confirmation of this, or to positively identify the individual.
Wilson's explanation is an urban legend, and there is no more evidence now on the identity of the killer than there was at the time of the crimes.
Two of the alleged "early" victims of the Axeman, an Italian couple named Schiambra, were shot by an intruder in their Lower Ninth Ward home in the early morning hours of May 16, 1912.
The male Schiambra survived while his wife died. In newspaper accounts, the prime suspect is referred to by the name of "Momfre" more than once.
While radically different than the Axeman's usual modus operandi, if Joseph Momfre was indeed the Axeman, the Schiambras may well have been early victims of the future serial killer.
According to scholar Richard Warner, the chief suspect in the crimes was Frank "Doc" Mumphrey (1875–1921), who used the alias Leon Joseph Monfre/Manfre.