Ann-Maria Myllgren (born Aino Kerttu Annikki Nykopp-Koski, November 1950) is a Finnish serial killer who while working as a nurse murdered and attempted to murder several of her patients in 2004 - 2009. Before the homicides she had been given provisory sentences for other crimes such as stealing medicine and patients' possessions.
Police started investigating Nykopp's actions after a poisoning case from March of 2009. According to a witness Nykopp had created a yoghurt meal which contained different life-threatening medicine. An elderly woman who had become a victim was healed at Maria Hospital. Many more similar poisoning cases were revealed during the investigation.
Nykopp denied having committed the crimes. She claimed that in some cases it was about natural deaths while in other cases the patients took too much medication themselves.
Helsinki's district court looked Nykopp on May 14th, 2010 on a ruling given by them as guilty of five murders, five attempted murders and two aggravated assaults and sent her to a mental health inspection. According to the inspection she worked in full understanding of what she did, and that she had antisocial personality disorder.
Nykopp was sentenced at the decision of Helsinki's district court on December 22nd, 2010 to a life sentence. Nykopp-Koski complained about the sentence and the case's handling in court of appeal started in the autumn of 2011. Helsinki's court of appeal decided on March 29 2012 with their sentence that Nykopp is guilty of five murders, five murder attempts, three aggravated assaults, two gross thefts, two thefts and two intoxicant-related crimes.
Court of appeal kept the sentence given by court of district in power. Highest legal authority in Finland administering justice in civil abandoned Nykopp-Koski's complaint permission request in November 22nd, 2012.
- Nykopp-Koski is the first known Finnish female serial killer.