The attacker, 19-year-old Reta Ann Wilson-Coughlan, had a succinct explanation for police: "She pushed me to my limit so I f...ed her up."
She appeared in the Dunedin District Court yesterday after pleading guilty to assault with intent to injure.
Sparks flew between the flatmates on August 21 when they had a conversation about Wilson-Coughlan allowing friends to bunk in her room over the previous month.
The defendant became enraged when the other woman informed her she had contacted their property manager about the situation.
"I’m going to f ... you up now," Wilson-Coughlan said.
She lunged at the victim, grabbed her by the shoulders and threw her through the doorway into the hall, a police summary of facts said.
Wilson-Coughlan punched her in the head, then dragged her to the ground by her hair.
She maintained her grip while she inflicted several more blows with her fist, the court heard.
Before other flatmates intervened, Wilson-Coughlan also kicked the woman a few times.
Judge Dominic Flatley was stunned by the prolonged attack.
"This was absolutely unprovoked. There was no reaction. You simply decided what you were going to do, you told the victim and then you did it
"There’s huge public interest in this. The public will be horrified that someone like you could attack somebody else in this way," he said.
The court heard the effect on the victim had been pronounced.
She had moved out of the flat, had undertaken counselling, feared for her safety and now struggled in social situations.
"It’s cost her a great deal," the judge said.
"All because you decided you were going to show her who was boss."
Counsel Brendan Stephenson said Wilson-Coughlan had been feeling isolated at the time and was willing to put in the work to ensure she did not react in the same way in future.
He argued for a sentence of community detention and supervision but Judge Flatley was not convinced.
"These are the actions of a violent bully and now you’re asking me to be kind, show you some leniency," he said.
Wilson-Coughlan was sentenced to five months’ home detention.
The only factors that saved her from imprisonment, the judge said, were her clean criminal record and her age.
