Mrs Steensen said Bruce "drew people to him like magnet" and the family still grieved his loss despite professional counselling.
"You can't go through life treating people like a punching bag," Mrs Steensen said.
"Please don't let it happen again.
"There is no shame in just walking away."
The court heard Patrick had a history of violence and anti-social behaviour but felt remorse for his actions.
His defence lawyer said it was likely Patrick, who has lived in Australia since he was 11 and is a permanent resident, will be deported to New Zealand at the end of his sentence.
-AAP