Fritz Haarmann's Overcoat

Origin
Friedrich Heinrich Karl "Fritz" Haarmann (25 October 1879 – 15 April 1925) was a German serial killer, known as the Butcher of Hanover and the Vampire of Hanover, who committed the sexual assault, murder, mutilation and dismemberment of a minimum of 24 boys and young men between 1918 and 1924 in Hanover, Germany.

Haarmann was known to dismember and eat the flesh of his victims, occassionally selling their meat on the black market as "horse meat." He also often kept souvenirs from each of his murders, most commonly clothes. One such souvenir was the yellow overcoat of 19-year-old Hans Sonnenfeld, who disappeared on or about 31 May, which Haarmann is known to have worn after the youth's murder.

When finally caught and faced with evidence, Haarmann confessed to his crimes of raping, killing, and dismembering young men in what he initially described as a "rabid sexual passion."

Effects
Wearing this overcoat does not have any immediate effects on the wearer. In fact, barring situations that induce its effect, users of the artifact behave completely normal, and it would be practically impossible to know they had been affected.

The effects of the coat only become apparent when the wearer becomes sexually excited, even after the coat is removed. During intercourse, the user will behave increasingly more passionate and rough until their climax, upon which the user will be immediately driven to murder their partner(s) by whatever means are immediately available.

After their excitement wears off, users will begin to behave normally again, and may react with great aversion to their actions immediately afterwards and over the coarse of several days, as would be considered normal. However, the passion of the moment will always be more powerful than any convictions they may have. In most cases, this includes subconsciously deterring wearers from turning themselves in for their crimes or from ceasing sexual activity.

Collection
This artifact was collected September 5th, 1985 by agents Nielsen and Sweetwood after a series of disappearing sex workers had been reported. After the artifact's user had been apprehended, Sweetwood underwent a complete mental breakdown induced by Vaslav Nijinsky's Music Box, which had been activated accidentally almost a week prior. Sweetwood was admitted to a local mental institution and his employment at Warehouse 13 was terminated the next day.