Elizabeth Tracey Mae Wettlaufer said she injected patients with lethal dosages of insulin when she poisoned residents who ranged in age from 75 to 90 in two Ontario facilities between 2007 and 2014.
According to CNN partner CBC News
, Wettlaufer, 49, told an interrogator that she was angry with life.
In the video, played during her one-day trial Thursday, she says she knew the difference between right and wrong. But she said she would get a "red surging with God telling me this is the one."
She also picked some victims because they were "mean," CBC News reported.
Victims James Silcox, 84, Maurice Granat, 84, Gladys Millard, 87, Helen Matheson, 95, Mary Zurawinski, 96, Helen Young, 90 and Maureen Pickering, 79, were residents at Caressant Care Nursing and Retirement Home in Woodstock, where Wettlaufer worked.
Arpad Horvath, 75, resided at Meadow Park Long Term Care in London, Ontario. which also was among the places Wettlaufer worked. Horvath died on August 31, 2014.
Wettlaufer also confessed to trying to kill others, the video shows.
Authorities received a tip in September that a nurse had killed multiple patients, which led to Wettlaufer's arrest, police in southwestern Ontario have said.
Wettlaufer said after she killed five people she began to doubt God was telling her to kill. Maybe it was the devil, she thought. There were no killings between fall 2011 and July 2013.
The former nurse told friends and a pastor what she had done, she claims in the video, which was recorded by Ontario Provincial Police in October.
"Maybe they didn't believe me," she says. "I don't know. Maybe they just thought I was doing something that the patient wanted."
Wettlaufer will be sentenced later this month and faces life in prison.