A nurse who methodically poisoned at least three patients to make sure they didn’t die on her shifts was sentenced to life in prison by a Japanese court on Tuesday. Ayumi Kuboki, 34, admitted to killing three people in Sept. 2016, saying she had added antiseptic into their IV drips. She was spared the death penalty by the Yokohama District Court after a judge noted she had shown remorse for the killings. Kuboki said during her trial she had intentionally orchestrated the deaths to occur when she wasn’t working, in order to avoid any “troublesome” conversations with grieving relatives. Prosecutors had requested the death penalty.

The nurse was arrested in 2018, two years after suspicions of an “angel of death” killer stalking the hospital were first aroused when two patients, both aged 88, were poisoned to death within days of one another. The nurse admitted to killing one other patient, a 78-year-old woman, but her true body count could be much higher, officials have said. Nearly 50 people in Oguchi Hospital, which closed in 2019, died between July and September 2016, but almost all of the bodies were cremated before any alarm bells were raised, making it impossible to ascertain if they were victims of poisoning.