Mrs Bennett then explains that she did not want to end up a "vegetable" or lose herself; nor did she want her family to suffer the heartbreak of her decline.
"It happened amazingly quickly. After about half an hour her eyes were open but I couldn't see her, her chest was not moving. It looked like she was gone. I waited another half hour and then I called our doctor and then the police were called."
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Assisting a person to end their own life is illegal in Canada and carries a maximum jail term of 14 years.
Police formally interviewed Mrs Bennett's doctor, husband and daughter. They concluded that Mr Bennett was not involved.
"I wasn't allowed to help her at any stage which was pretty hard. But the law here is pretty clear," Mr Bennett said.
"But I was with her. That, I was allowed to do. I knew all along what she was going to do, and that is legal. She was extremely anxious not to get anyone in any legal or criminal trouble."
Mrs Bennett, a child psychologist, had always been passionate about the right to die.
"She was vigorously opposed to the resources that are put into simply keeping the heart beating in a body that wouldn't allow a person any sort of life," Mr Bennett said. "It is no good for the person, it is use of the time and talent of doctors and nurses and it's a frightful waste of money.
"That was a very strong view of hers for as long as I knew her. It has always been clear that she would not go out that way."
Mrs Bennett wrote: "Every day I lose bits of myself, and it's obvious that I am heading towards the state that all dementia patients eventually get to: not knowing who I am and requiring full-time care. I know as I write these words that within six months or nine months or 12 months, I, Gillian, will no longer be here. I have choices which I have reviewed ... I think I have hit upon the right choice for me."
Since Mrs Bennett's death, her letter has been read by almost half a million people.
"Above everything else, Gillian wanted to get a conversation going - and by God, has she," said Mr Bennett. "I am very proud of her. I miss her horribly but I have no sense that 'oh, this was a mistake'." ... "
Assisted suicide is illegal in New Zealand. Under Section 179 of the Crimes Act 1961, anyone convicted of inciting, counselling or procuring another person to commit suicide or physically helps them in any way to take their own life faces a maximum of 14 years in prison.
Final Message
Extracts from Gillian Bennett's farewell letter
I will take my life today around noon. It is time. Dementia is taking its toll and I have nearly lost myself. I have nearly lost me. Jonathan, the straightest and brightest of men, will be at my side as a loving witness.
There comes a time, in the progress of dementia, when one is no longer competent to guide one's own affairs. I want out before the day when I can no longer assess my situation, or take action to bring my life to an end.
Every day I lose bits of myself, and it's obvious that I am heading towards the state that all dementia patients eventually get to: not knowing who I am and requiring full-time care. I know as I write these words that within six months or nine months or twelve months, I, Gillian, will no longer be here.
I have had a husband beyond compare, and children and grandchildren who have outstripped me in most meaningful ways. Since I was seven I have had wonderful friends, whom I did and still do adore.
Today, now, I go cheerfully and so thankfully into that good night. Jonathan, the courageous, the faithful, the true and the gentle, surrounds me with company. I need no more.
It is almost noon.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (4pm to 6pm weekdays)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.
