His father was an alcoholic and locally regarded as an ill-tempered brute, who was often arrested for starting fights with other townsfolk, also regularly beating his wife and children in drunken rages using a fire poker.

Großmann was often singled out in the abuse, as his father "hated how alike they were", and forced his son under threat of death to lie to teachers about the bruises, claiming that they were the result of accidents while playing.

[4] In 1876, he took an apprenticeship as a slaughterhouse worker at the meat shop of Ferdinand Kliefoth, who took the troublemaking youth in despite his unpopular reputation, having seen his potential as a slaughterer given his deftness with a knife and lack of aversion to blood.

Between 1886 and 1887, Großmann served in the Imperial German Army, in the 12th Grenadier Regiment in Frankfurt an der Oder (most likely referring to Grenadier-Regiment „Prinz Carl von Preußen“ (2.

[7] Upon his release in 1890, Großmann worked for numerous butcher shops and slaughterhouses in Berlin-Mitte, subsidizing his income as a peddler of matches and other households items.

[4][5] Großmann left Berlin in 1894 after failing to find steady employment and became a vagrant traversing southern Germany during the late 1890s, making a living through begging, peddling, and theft.

On 3 January 1896, a gardener couple had alerted police after hearing their nanny goat screaming, with officers finding Großmann inside the stable, at the hooves of the animal and hiding under an Inverness coat.

He first claimed to have only trespassed for nightly shelter, but an examination of the goat showed that it had severe swelling around the genitalia while Großmann was "wet around the knees" and had the fly of his pants open.

A court in Bayreuth sentenced him to 15 years imprisonment for the rapes on 4 October 1899; the four-year-old died of an infection from a complete tearing of the perineum inflicted during the attack shortly after the judgement.

During his sentence at Ebrach prison, Großmann continued his violent behaviour and got into unprovoked fights with fellow inmates, leading to 55 citations.

Initially financing himself with peddling, Großmann rented out the kitchen habitation in the third-floor apartment of Mannheim Itzig at Lange Straße 88, in the area around Berlin Ostbahnhof, known at the time for its high rates of crime, unemployment, and prostitution.

Residents admitted to often hearing loud noises and screaming from his flat, but did not think more of it, believing Großmann was only having rough sex with prostitutes, which was not uncommon in the quarter.

[1][3] Beginning at least 1918, Großmann used his location near Ostbahnhof to approach women, often job-seekers from the countryside newly arrived by train, and lure a victim to his home by offering them work as a domestic housekeeper.

At the apartment, Großmann would physically overpower the woman and rape her, though other times, he would let the victim do housekeeping for several days or weeks before drugging and sexually assaulting her.

After any encounter, Großmann reported the women, whether dead or alive, to police, claiming they had run away after stealing from him to either explain their disappearance or disparage potential accusations made by surviving victims.

On occasion, Großmann also targeted local women, ranging from female labourers, stay-at-home mothers, and sex workers, all invariably from poor financial backgrounds.

Entering his room, Itzig first believed she had only caught Großmann sleeping with a sex worker, but was horrified when she pulled away the blanket and found that the woman was motionless and had a broken bleeding nose.

Negative and hostile attitudes against sex workers were widespread at the time,[1][11] so Itzig did not question this further and left after being paid off with 50 DM, supposedly to keep quiet about his solicitation habits.

In August 1921, at least twelve people answered the request, leading to three possible, but unconfirmed identifications as Else Thiese, Margarete Simon, and Wilhelmine Poppel, as well as one accusation against a certain Ernst Brandt, which was also not investigated.

[4] It was rumored and widely reported by contemporary newspapers that the meat Großmann sold contained the remains of his victims, as he threw some of their bones and other inedible parts into the river.

On 21 August 1921, a neighbour of Großmann, labourer Robert Iglitzki, was awoken by his wife, who had heard screams and banging noises from above, followed by silence at around 21:30.

[10] Witnesses confirmed that Nitsche had been picked up by Großmann at Koppenstraße and that the pair spent the evening at a nearby carnival, using rides and drinking beer, until around 21:00.

This was observed by long-time sex workers in the borough, who had given him the nickname "Mysterious Karl", as they did not know Großmann's intentions, avoiding him as a client and telling newcomers to decline his alms.

She was 25 years old and an unemployed feedlot worker at the time, stating that she was not assaulted by Großmann, instead leaving without issue after drinking beer with him and being given a new pair of shoes.

During his arrest and two weeks into custody, he would firmly contest that he had killed Nitsche because she had stolen from him, and attempted to convince officers to downgrade his murder charge to manslaughter.

By June 1922, Großmann had reportedly begun writing an autobiography in which he claimed that he killed his victims because they were "surplus women", whom he described as "economic and social pests".

[20][8][16] A medical assessment by Medizinalrat [de] Robert Störmer, who also personally met with the arestee, examined Großmann's familial history, including that of his father's previous wives, their husbands, and their children, and prior criminal arrests.

His younger brother, Wilhelm Großmann, was treated at two Weißensee asylums for "cerebral softening" before at Martin Gropius Krankenhaus in 1911 at age 39, but this was believed to have stemmed from a severe head injury during work and an untreated syphilis infection.

Großmann had retracted his initial confession and now repeated his claim that he only killed his victims because they stole from him, accusing the witnesses of telling "pure lies" and being "ungrateful to [his] hospitality".

[3][15] On the third day of the main trial, as judicial officers found Großmann dead in his cell at Justizvollzugsanstalt Moabit [de] when they came to transport him to court.