WOODSTOCK, Ontario -- A Canadian former nurse convicted of killing eight elderly people in her care was sentenced Monday to life imprisonment without possibility of parole for 25 years.

Elizabeth Wettlaufer pleaded guilty last month to eight counts of first-degree murder, four counts of attempted murder and two counts of aggravated assault in the notorious serial killings. The 50-year-old told the court on Monday that she is truly sorry and hopes her victims' families can find peace and healing.

"I caused tremendous pain and suffering and death. Sorry is much too small a word. I am extremely sorry," she said in court, according to the Canadian Broadcasting Corporation.

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Authorities have said the 14 assaults on patients took place over the last decade in three Ontario long-term care facilities where Wettlaufer worked as a registered nurse, and at a private home. Wettlaufer admitted to using insulin in all of the cases from 2007-2016.

"It is a complete betrayal of trust when a caregiver does not prolong life, but terminates it," Justice Bruce Thomas said. "She was the shadow of death that passed over them on the night shift where she supervised."

Susan Horvath, a daughter of victim Arpad Horvath, said she did not read her victim impact statement because she couldn't trust herself being too physically close to Wettlaufer in the courtroom.

"I am too angry," she said. "I didn't trust myself up there."

Laura Jackson, the friend of one of the victims, said Wettlaufer "should spend the rest of her life in a small box contemplating what she's done. It wasn't rash. It was thought out. It was calculated."

Shannon Emmerton, the granddaughter of another victim, said other nurses could potentially commit the same crime. The Ontario government launched a public inquiry soon after the sentence was announced.

"We want to assure the public that Ontario's 78,000 long-term care residents are safe in their homes," Ontario's attorney general said in a statement. "It is our hope that through the inquiry process, we will get the answers we need to help ensure that a tragedy such as this does not happen again."