Kael Leona will spend at least 12 years behind bars for the murder of Bernice Louise Marychurch.
Leona had pleaded guilty to her murder, as well as a separate strangulation.
Justice Layne Harvey sentenced him to life in prison with a minimum non-parole period of 12, and 12 months for strangulation served concurrently.
Bernice Louise Marychurch died in October 2024 after she was stabbed roughly 20 times on the Number 74 bus in Onehunga.
There were nine other people on board the bus at the time.
Kael Leona, 37, was charged with murder, after handing himself in to police.
Leona previously plead not guilty on grounds of insanity but at a hearing at the High Court in Auckland in February, he entered guilty pleas to murder and strangulation.
The High Court at Auckland has been hearing evidence on Wednesday morning on a disputed mitigating factor.
Leona's defence have called Dr Angela Ryan as a witness. She said her preferred diagnosis for Leona was schizophrenia.
In a social media post following the murder, Marychurch was described as a loving, beautiful and devoted mother.
A passenger on board the bus that day told RNZ she wanted the victim's family she and the other passengers tried to help.
"I just want to let her family know that she didn't die alone, that I held her hand in the bus until she got help and we did everything we could."
SHARE ME