Joachim Knychała was born in Bytom on September 8, 1952. His father was Polish and his mother German, and he was raised by his mother and a domineering grandmother in a Protestant family. Polish sources record that his grandmother never forgave her daughter for marrying a Polish man and turned it on the child; both women called him a Polish bastard, and other children called him the German. He left school in 1967, trained as a miner and carpenter, and went to work at the Andaluzja colliery in Piekary Śląskie, where he lived.
As a young man he took part in the gang rape of a girl and served three years for it. He maintained he had been framed by her. Accounts of his time in prison describe a hatred of women forming there. After his release he married and had children, and at home was regarded as a model husband and father.
His first attack was on November 3, 1974, in a block of flats on Wrocławska street in Bytom. He hit a twenty-one-year-old woman on the back of the head with great force; a thick hat saved her, and she saw his face. The second attack, about a year later, killed. A third followed on May 6, 1976. He struck from behind with an axe, and several of the women he attacked survived with permanent injuries.
He was careful in a way the investigation found hard to counter. He never attacked after drinking. He avoided public transport on the way home. The weapons he used were not his own. He put himself down for night shifts at the mine, which gave him an alibi on paper.
He was detained and questioned for the first time in 1979. One of the surviving women identified him. He was not charged, because of the alibi, and he stopped attacking for about two years.
What ended it was a killing inside his own family. His seventeen-year-old sister-in-law, Bogusława Ludyga, was murdered, and he telephoned the ambulance service himself to report that a woman had fainted. The examination found she had died from a blow with a blunt instrument, and there was semen on her underwear. He was arrested, denied everything through the early interviews, and eventually gave an account of all of it.
He told investigators that he had attended the trial of Zdzisław Marchwicki, the Vampire of Zagłębie, and that what he heard there had inspired him to become the next vampire. The police file on him was codenamed Frankenstein, and both that and the Vampire of Bytom stuck.
The provincial court in Katowice sentenced him to death on April 19, 1984 for five murders and seven attempted murders. He heard it without saying anything. He had contested parts of the case, challenged witnesses and pointed out the militia's mistakes. The Supreme Court upheld the sentence that October. He tried twice to kill himself in custody and was revived both times. He asked to see his children and was refused; his mother and his wife visited.
He was hanged at the prison on Montelupich street in Krakow at half past five in the evening on May 21, 1985. He was thirty-two.
Reporting from the period was thin, and the case has been reconstructed since largely through books and documentaries rather than contemporary coverage. Sources disagree over the year of the last killing, some placing it in 1982 and others as late as 1984; the 1982 date is consistent with the investigation timeline and is used here.