Ferdynand Grüning

Ferdynand Grüning or Ferdynand Grining (6 August 1885 – after 16 August 1939), known as the Łódź Vampire , was a Polish serial killer and child rapist who killed three children across Poland from 1926 to 1938 during the interwar period. He was sentenced to death for his crimes, but due to the outbreak of the Second World War shortly after, it is unknown if this sentence was carried out. His freedom did not last long, as he was sentenced to a year of imprisonment for theft. The boy's skeleton was found in a field by a farmer in the village of Piaskowice Pieńki six weeks later. He was identified by a cap with his name and surname etched onto it, bearing the signature "Józef Chudobiński, cl. IV".

On 8 July 1938, Grüning raped and attempted to kill 8-year-old Lucyna Góra in Piotrków Trybunalski, but she managed to escape. Throughout the proceedings, Grüning sat on the bench with his head lowered and his eyes staring at the floor, and when he was asked questions, he claimed that he did not know the answers.

Despite his denials, Chudobiński's friends testified before the court and identified him as the mysterious man who had talked to their friend shortly before his abduction; similar testimonies were also given by Lucyna Góra, the family members of other victims and Grüning's own siblings.

Eventually, he was convicted on all counts, receiving three death sentences for two counts of murder and rape, and a single count of attempted murder. In addition, he was deprived of his rights for life. At the sentencing phase, the court emphasized on Grüning's "lack of human instincts, animalism and cruelty", and upon hearing the sentence, he accepted it calmly and without no apparent emotion.

After he was sent to prison, it is unclear whether Grüning's sentence was carried out. The last confirmed fact known about him is that on 16 August 1939, when his brother was being tried for theft, he was registered as still being in prison. Two weeks after that, the Second World War began, and all traces of him after this point are lost.