Prosecutor Cameron Stuart said it was important to recognise it was not a mercy killing or an assisted suicide. He said it was not an act of desperation or last resort.
"Suicide in these circumstances cannot be condoned and must be condemned."
He said it must be emphasised that there is help out there, and there is no shame in seeking it when needed.
Judge Rea said it was vital to emphasis that a suicide pact is defined as an agreement which two people enter into with the objective that both of them will die.
He acknowledged the level of emotion was justifiably understandable.
"There was an act of deliberation between he and his wife that they would both take their own lives."
He said the fact that Spensley survived does not change the fact that he intended to die as well.
"These cases are never easy for anybody that is involved in them. In my view a conviction and discharge is the appropriate response."
Elaine Spensley's second eldest daughter, Susan Smith, read an emotional victim impact statement during the sentencing.
She said Elaine's four children had all loved and cherished their mother, and had tried to accept Spensley as a step-father.
"This was not a romantic notion of two elderly lovers dying together, as only one of them died that day."
The police summary of facts stated that Spensley, and his wife Elaine, who lived in Palmerston North, entered into the pact on April 5, 2018.
The couple, who had been married for 23 years, were living in Palmerston North.
Elaine had been in hospital in March 2018, but was discharged and recovering at home.
On April 5, Elaine went to see a doctor, who ordered some tests and sent her home pending results.
It was suspected she had an adverse reaction to antibiotics prescribed to her when she was discharged from hospital.
The couple entered into an agreement to commit suicide together that same day.
They wrote several letters, addressed to the police, coroner and the couple's children.
Spensley also placed a letter in a neighbour's letter box, intending for him to find it the next morning, which he did.
The neighbour contacted police, who the found couple lying on the bed next to each other, Elaine deceased but the defendant still alive.
Detective Senior Sergeant Craig Sheridan said police acknowledged the judge's decision.
"This was a challenging case for the investigation team and I would like to recognise the work of everyone involved in achieving the outcome today.
"I would also like to acknowledge the family of Elaine Spensley.
"Their strength as a family and commitment to honouring their mother, grandmother
and great-grandmother has been resolute."
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
OR IF YOU NEED TO TALK TO SOMEONE ELSE:
• 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP) (available 24/7)
• https://www.lifeline.org.nz/services/suicide-crisis-helpline
• YOUTHLINE: 0800 376 633
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757 or TEXT 4202
