In 1919, Tillie married again. Her third husband, Frank Kupczy, moved into the apartment she had shared with her late boyfriend. Tillie began telling neighbours that Frank “would not live long” and he had “two inches to live”. She even taunted him, saying “It won’t be long now,” and “You’ll be dying soon”. Frank soon grew weaker, and she began to plan his death: Tillie asked Frank to take out a life insurance policy. He complied. She took this opportunity to knit a black mourning hat, which she later wore to trial, and purchased a $30 coffin from an advertisement. Tillie even asked her landlady to store the coffin in the basement of the building until her husband’s death. Frank died in 1921.
Regardless of her reputation of premonitions with subsequent deaths of all her husbands, she was still able to find a fourth man willing to marry her. In 1921, Tillie married her fourth husband, Joseph Klimek. A former friend of her late husband Frank. Joseph was thrifty, had a steady job, and wanted to settle down. Tillie was a good housekeeper and an astonishingly good cook. To commemorate their marriage, Tillie destroyed every photo and letter she had of ex-husbands and ex-boyfriends. Joseph, infatuated, thought this was touching and a sign of loyalty, instead of a warning sign.
When Joseph became ill the following year, he called his doctor. Joseph was sent to the hospital, and tests confirmed it: he was dying of arsenic poisoning. Tillie was arrested.
Tillie claimed that Joseph was an alcoholic who not only enjoyed moonshine too much and too often, but also abused her and cheated on her. Tillie, however, would not tolerate competition. Tillie told the police that she had confided in her cousin Nellie that she was tired of her husband Joseph. Nellie suggested divorce, though Tillie said “I will get rid of him some other way,”. Tillie claimed that Nellie had given her a poison called “Rough on Rats”.