Ludwig Tessnow
[2]: 51-52 Consequently, although investigators had been unable to prove extensive staining found upon Tessnow's clothing following his 1898 murders was wood dye, as he had claimed, or human blood, by the time he committed his 1901 murders, pioneering precipitin testing enabled investigators to prove his clothing had been extensively stained with both human and animal blood, despite his claims to the contrary.
[3]: 202 The tests conducted by biologist Paul Uhlenhuth upon Tessnow's clothing proved to be the first instance in which the forensic analysis of bloodstains was used in the conviction of a criminal.
Later that evening, local police discovered the nude body of Else Langemeier concealed within bushes close to where Heidemann had been found.
[n 2] Tessnow made no attempt to leave Lechtingen, and was observed wearing this stained clothing on several subsequent occasions.
[3]: 201 On the evening of 1 July 1901, two young brothers named Hermann and Peter Stubbe (aged eight and six) disappeared in the Baltic resort of Göhren, having informed their parents of their intentions to play near the family home.
[2]: 49 Police questioning of all local residents produced one eyewitness who stated she had observed the brothers talking with a "journeyman carpenter" named Ludwig Tessnow on the afternoon of their disappearance.
A routine search of his home revealed several items of clothing which, although still damp from having been recently washed, bore dark stains reminiscent of blood.
[8] Tessnow admitted to having read newspaper reports of this incident but also protested his innocence in the killing of the sheep; again insisting the stains upon his clothing and boots were not human or animal blood, but wood dye.
[3]: 202 Having read Tessnow's statement, the examining magistrate, Johann-Klaus Schmidt, noticed similarities between his accounts of wood dye being the source of the stains on his clothes and the excuse given by a potential suspect in the 1898 murders of two children near Osnabrück.
[2]: 51 Shortly before the murders of the Stubbe brothers, a German biologist, Paul Uhlenhuth, had developed a method that allowed the detection of human and animal blood: the precipitin test.
The decision was approved and two separate packages containing Tessnow's clothing and footwear, plus the stained stone recovered at the Stubbe crime scene, were sent to Uhlenhuth on 29 July and 1 August.
[2]: 52 On 8 August 1901, Uhlenhuth submitted a report, dated 5 August, to police in which he conclusively determined that although some stains upon Tessnow's overalls,[8] clothing and shoes were actually wood dye, the vast majority of the stains upon his clothing were human blood, with some bloodstains found upon Tessnow's jacket and trousers also sourcing from sheep.
[3]: 202 [n 5] The forensic methods used by Paul Uhlenhuth to identify the origins of bloodstains via precipitin testing were officially introduced as court-proven evidence in Prussia on 8 September 1903.
