The Ax Man Strikes Again in New Orleans

There are reports of similar murders taking place as early as 1911, and as far west as Texas. The ax man himself sent a chilling letter, taunting the police and threatening to kill more innocent people. No one knows his or her identity. Or its identity. What if the ax man isn't even human? Wait, well of course he's human. But we don't actually believe that, right? Right? I'm just saying, if the ax men were invisible, it would explain why he or it hasn't been caught.