The question of whether former nurse Elizabeth Wettlaufer believed herself an angel of mercy, acting on the instructions of her elderly patients, was answered in her chilling videotaped confession to police played publicly for the first time this week.

The former nurse — who pleaded guilty to killing eight seniors in her care and attempting to kill or assault six others Thursday — offered many explanations for her actions in the 2½-hour-long interview conducted by Ontario Provincial Police on Oct. 5, 2016.

But none of those involved a request for assisted suicide.

Elizabeth Wettlaufer tells officer how she chose one of her victims0:44

'I knew the difference between right and wrong'

Instead, Wettlaufer said she believed that either God or the devil wanted her to kill these people. That she would be visited by "surges" that she could not control. And that she picked some of her victims because they "were mean," difficult to look after and she had a heavy workload.

That said, Wettlaufer told the detective that she understood that she was administering what would prove to be a lethal dose of insulin to eight people.

'I knew the difference between right and wrong': Elizabeth Wettlaufer0:13

"I knew the difference between right and wrong, but I thought this was something God, or whoever, wanted me to do it," she told the officer. "But I was starting at that point to doubt that it was God."

At that point in her confession, Wettlaufer is speaking about the murder of Helen Young, her sixth known victim, whom she killed in July 2013. Young was the first person she had killed since 2011.

Elizabeth Wettlaufer describes how she killed a patient0:34

Wettlaufer has admitted guilt to eight murders between 2007 and 2014.

In the video, she recounts the killings in detail, often citing the lethal dosage of insulin she used. She notes which patients seemed peaceful and who fought the injection. And she speaks for longer whenever the victim is one she found frustrating to care for.

'I thought, I don't want her to die, but if I could somehow give her enough [to] give her a coma [and] make her less hard to handle.' - Elizabeth Wettlaufer

"Maureen [Pickering] was a handful," she tells the detective, of a 79-year-old woman with dementia.

Pickering received one-on-one care because she could be aggressive with other patients, Wettlaufer said.

"She just got harder and harder to look after and, one night, when I had to look after her … I was starting to get the feeling, that surge again," she said. "I thought, I don't want her to die, but if I could somehow give her enough … to give her a coma or change her brainwaves, maybe make her less mobile, less hard to handle.

Elizabeth Wettlaufer would start 'cackling' after fatally injecting patients0:20

"So, yeah, I overdosed her."

And although the ex-nurse makes several apologies to her victims' families throughout the video, she does not do so after describing Pickering's death, nor after talking about that of another "mean" patient.

Instead, she talks about how she felt.

"The surging," she said. "And then the laughter afterwards, which was really, it was like a cackling from the pit of hell."

Elizabeth Wettlaufer apologizes to victims’ families in confession1:16

Disclosure

But Wettlaufer tells the detective that she tried to stop killing.

Wettlaufer was arrested after she told staff at the Centre for Addiction and Mental Health psychiatric hospital in Toronto what she had done. But in her confession to police she said she already had told friends, a former partner and her pastor about the killings, saying she wished she'd "gotten help sooner."

"Maybe they didn't believe me," she said in her interview with police. "I don't know. Maybe they just thought I was doing something that the patient wanted."

Wettlaufer tells the detective that she feels both guilt and shame. When asked by the detective what she might say to her victims' families, Wettlaufer exhales.

"What can you say to them that would matter? I'm sorry isn't enough," she said. "I should have gotten help sooner. I took something from you that was precious and was taken too soon."