When the police searched Aino Nykopp-Koski's possessions they seized more than 1,800 doses of narcotic and sedative drugs. She was a practical nurse in Helsinki, about fifty-nine, working in home care and in care institutions, often through agencies and moving often between employers. The drugs were not part of any treatment she had been asked to give.
Between June 22, 2004 and June 12, 2009, the courts found, she brought those drugs with her to work and secretly gave them to elderly patients too frail to resist, mostly sedatives, among them diazepam, along with opioids such as oxycodone. Five of them died. Five more were poisoned and survived. Her victims were between seventy and ninety-one. She also stole from them: money, jewelry and their own medicines. Because she moved from one employer to the next, the deaths were spread across several places and no single one saw a pattern.
She had a record before any of it, with earlier convictions for theft of drugs, criminal damage and a narcotics offense. She was arrested in 2009, and the deaths at her earlier workplaces were then re-examined.
The Helsinki District Court convicted her in December 2010 of five murders and five attempted murders and sentenced her to life. The date of the judgment is given as December 21 and as December 22. A psychiatric examination found that she had an antisocial personality disorder with marked psychopathic traits and that she was criminally responsible.
She denied everything, in the district court and again at the Helsinki Court of Appeal, where the case was heard in the autumn of 2011 as the largest serial murder case in Finnish legal history. Her lawyer, Heikki Lampela, told reporters that she believed with every cell of her body that she had been doing good and valuable nursing work. On March 29, 2012 the appeals court upheld the life sentence, finding that the murders and attempts had been committed with premeditation. It added three aggravated assaults, two aggravated thefts, two thefts and two narcotics offenses. The Supreme Court refused leave to appeal on November 22, 2012.
No motive was established beyond the thefts, and she never offered one.
After her conviction she changed her name to Ann-Maria Myllgren. A Finnish life sentence can end in parole after a minimum of twelve years, which in her case would have been March 2021. She applied, and in May 2020 the Helsinki Court of Appeal turned her down. It noted that her conduct in prison had been good, but held that the number and nature of her crimes meant she should serve clearly longer than the minimum. A later application, made when she was seventy-two and had served more than thirteen years and eight months, was also refused.