Denke was born on 11 February 1860 in Oberkunzendorf, north-east of Münsterberg, Silesia, in the Kingdom of Prussia (now Ziębice, Poland), to a family of German farmers.

[1] Little is known of Denke's childhood, but it is known that he was often described as a quiet and soft-spoken child who was difficult to raise, being noted as one of the worst students at his elementary school.

He acquired a vending licence and ran a nearby shop where he sold goods made from leather and boneless meat (which most speculate to have contained human remains).

Six years later, in 1909, he killed 25-year-old Emma Sander (another slaughterhouse worker, Eduard Trautmann, was found guilty of her murder, but was released in 1926 after the truth was discovered).

[7] On 21 December 1924, Denke lured a homeless drifter named Vincenz Olivier into his home with the promise of twenty pfennig if he wrote a letter for him.

According to Olivier, he had sat down at a desk after being handed a pen and paper, but turned to his host after becoming perplexed when Denke dictated "Adolph, du fetter Wanst!"

[8] Initially, Olivier's testimony was disregarded due to Denke's reputation among the townsfolk, leading to his arrest for vagrancy and panhandling.

[3] They also discovered several items, including shoes, belts, braces, and shoelaces, that analysis determined were made with tanned human skin.