The 33-year-old man, named as Daniel S., suffocated his elderly neighbour in January 2012 and then drowned his 50-year-old girlfriend in their bathtub six months later.
After suffocating the 70-year-old woman with a plastic bag in her house, “probably because she was getting on his nerves,” he turned to her cat, state prosecutor Otto Röding in the town of Konstanz, Baden-Württemberg, told The Local.
The metal worker beat the animal to death with a baseball bat in his neighbour’s garage, filming it on his phone.
He then roasted the cat, before eating it with mashed potato, said Röding.
The prosecutor added that the court “did not find him to be suffering from mental illness.”
The double murder came to light last February, when the man raped two women he knew. “He threatened one of the victims, telling her that if she did not do what he said he would kill her like the cat,” Röding explained.
State prosecutor Regine Weinacht told the Bild newspaper that “he wanted to kill both of the women that night.” Instead, one escaped and alerted the police, and officers began looking into the two murder victims' deaths from 2012.
The court heard how the man laid his murdered neighbour back in bed, in an attempt to make it look like she died of natural causes. He also continued to live in his girlfriend's house, despite drowning her there. And he was only foiled more than a year later when he raped the two women.
The father-of-two initially confessed to the murders to police but later withdrew his statement.
However, the judge found him guilty on Thursday and said: “The women annoyed him, they had to go.”
He was convicted of murder, rape, serious physical abuse and dangerous bodily harm by the Baden-Württemberg court.