Seven years ago, the University of Goettingen had her head burned in a crematorium, which she had stored in formaldehyde for 89 years. This head was separated from the body in 1925 by a guillotine. One of the most horrible German serial killers ended up on the gallows. “Fritz Haarmann, also known as the Butcher of Hanover, murdered over two dozen young men between 1918 and 1924. After he was beheaded, his head was kept for research purposes, “writes the AP agency.