Isabella Mueller (crime writer)
Thallium is a heavy metal which, like arsenic, was formerly used as rat poison because it is odourless and tasteless. However, it is not only lethal to rats, but also to humans. One man who used it as a lethal murder weapon is 42-year-old nurse Manuel H., who treacherously poisoned three women with it, only one of whom survived. The series of murders caused a major stir in the media, which dubbed them the ‘Thallium Murders’. Until his crimes were uncovered, Manuel H. was regarded as a likeable man whose passion was competitive dancing. He grew up in a well-off family and took his A-levels in Solingen. After completing his community service, he wanted to become a pilot but failed the entrance exam. He then began two degree courses, both of which he dropped out of, before successfully completing his training as a nurse. Manuel had a string of relationships before getting married for the first time in 2011. However, the marriage ended in divorce after three years. From then on, he tried his luck on dating platforms. It was there, in 2015, that he met his future wife, a dedicated teacher, whom he married on Norderney in 2017. Their happiness seemed perfect. The couple lived in a house in Leverkusen until Manuel’s wife was admitted to Leverkusen Hospital in May 2020 due to severe paralysis. Her condition deteriorated despite medical treatment. After being placed on a ventilator, she was transferred to Düsseldorf University Hospital, where she died on 29 May 2020. The doctors assumed that Manuel’s wife was suffering from ‘Guillain-Barré syndrome’, an autoimmune disease that can lead to muscular paralysis. No one harboured even the slightest suspicion that she might have been poisoned by her husband. Manuel played the part of the grieving widower all too perfectly. Manuel not only inherited their shared house in Leverkusen, but also a large five-figure sum of money. In addition, he collected his wife’s life insurance payout. Just three months after his wife’s death, Manuel already had a new partner by his side, whom he had met via a dating platform. Her name was Yvonne K., also a teacher, who proudly introduced her new partner to her 92-year-old grandmother. Despite her advanced age, the grandmother still lived alone in her house in Hürth. However, following visits from her granddaughter and her new boyfriend, the grandmother’s health steadily deteriorated until she passed away on 1 April 2021. Given her age, the doctor assumed the cause of death was natural. From then on, the couple lived in the grandmother’s house. Then, in mid-August, Yvonne K. became pregnant and suddenly, like her grandmother, began suffering from diarrhoea and severe abdominal pain. She was admitted to hospital, where she had to be put on a ventilator in mid-November. But what was the cause of Yvonne’s pain? The doctors were able to answer this question on 26 November, as they diagnosed Yvonne with thallium poisoning and were able to save her life with an antidote. Yvonne did give birth to the baby, a girl, but the baby died shortly after birth. In the meantime, Yvonne’s mother had contacted the police. Her daughter’s symptoms had been far too similar to those of her late mother. The police took up the case and discovered that, since 2020, Manuel had been making contact via a sperm donor platform with women who wanted to have a child with him. He was operating under the name ‘Thomas Meinhard’. In total, he had been in contact with 37 women. Despite his new relationship with Yvonne, he continued these arrangements. During a house search in Hürth, the police found a loaded potassium chloride syringe in Manuel’s jacket. Potassium chloride causes cardiac arrest and is difficult to detect. It is presumed that Manuel intended to use this to get rid of his pregnant partner once and for all, after the thallium poisoning had failed. He had already redirected Yvonne’s bank accounts to his own. It would be mischievous to think the worst of him. Furthermore, Manuel had Googled the terms ‘thallium and pregnancy’. In light of the new evidence, the bodies of Manuel’s second wife and Yvonne’s grandmother – both of whom had been poisoned with thallium – were exhumed. Despite the overwhelming weight of evidence, Manuel maintained his innocence. He later claimed that his second wife had wanted to take her own life using thallium. That was why he had obtained it for her. After her death, he had found a suicide note in the safe, but had burnt it at her grave. These stories sounded preposterous. Manuel H. was sentenced by the Cologne Regional Court to life imprisonment with aggravating circumstances, followed by preventive detention, for two counts of murder, attempted murder, grievous bodily harm and attempted termination of pregnancy. This means that Manuel H. cannot be released after serving his minimum sentence of 15 years and may remain behind bars for the rest of his life.
