Why did Martha Haney decapitate her Mother-In-Law with an ax?

And how mental illness played a role in this gruesome murder

One of Michigan’s most horrific murders occurred back in 1897. Police had been called to the house at 320 Elevator Street near the local railroad tracks. When police entered the home, they saw that the floor was covered in blood. Within the pool of blood were clumps of hair and dents in the floor like someone had hit it with a heavy weapon. Police saw a trail of blood leading out of the room like someone had dragged a body…