Police were called to the scene and took him to the station, but Ms Te Ua Wiri is unhappy they let him go and still considers him a potential threat.
"The police called me up and said they couldn't hold him; I said, 'What do you mean? Our lives have been threatened'.
"That really freaked us out - I said, 'What is the point of ringing if you're going to let him loose ... he's going to come back again'.
"Where's the safety at? They pick up drunks and take them back to the cell, and all I wanted was one night, so I could go down to the courthouse in the morning."
Her nephew did not return, but Ms Te Ua Wiri says she would like systems in place to ensure such incidents do not happen again to others.
"I'm not trying to drag down the police. I just think there needs to be more places where people like this can be put and cared for."
She believes her nephew - who had been living with her for two months before the incident - has mental health issues. Now she says she's had enough.
"I took out a trespass order that night - he needs to be put into care."