One of the teenagers charged with the murder of a 78-year-old Opotiki man has given evidence at the High Court in Rotorua.

Eighteen-year-old Courtney Churchward has pleaded not guilty to murdering John Rowe in his home in November last year, as has a 15-year-old co-accused.

Churchward told the court she wanted to burgle Mr Rowe's home for valuables in order to get cannabis. She said she wanted to 'knock him out for a few minutes' while she robbed his home.

The teenager said after hitting Mr Rowe repeatedly and failing to knock him out, she though she must have been doing something wrong. When she turned on the light, she said she could see the injuries he had suffered and she ran off.

Churchward told the court she lied to police when she was interviewed, telling officers she was the only person involved in the attack to protect her co-accused.

The 18-year-old said she thought she was evil due to all her wrongdoing and the mistakes she has made. She said at the time of the attack she felt self hatred and inner-anger which fuelled the attack on Mr Rowe.

Churchward also spoke about the violent relationship she had with her former partner, where she was repeatedly beaten. She said her ex told her to 'act in a mental way' as it could help her case.

Mr Rowe's family sat in the gallery visibly upset and supporting each other through her evidence.

The judge ordered the trial to stop at one stage after a man in the public gallery caused interruption to the court. After rolling a cigarette in the gallery and refusing to leave when asked by the registrar, police arrested him.

The man was unknown to both the accused and victim's families.