A two-time rapist has received an indefinite jail term for the attempted sexual violation of a teenage girl.

Justin Ames Johnston, 41, has been sentenced in the High Court at Wellington to preventive detention with a minimum non-parole period of six years.

He has also received a concurrent sentence of six months' for threatening grievous bodily harm to her father, who chased him at the scene.

In December last year, Johnston was found guilty of attempted sexual violation of the teenager.


The father of the girl discovered Johnston in the backyard the Upper Hutt property where the 16-year-old was alone in a sleepout.

Johnston claimed to have been on the suburban section intending to commit a burglary.

However, the jury of six men and six women returned a unanimous guilty verdict.

Johnston had also changed his plea to guilty on a second charge - threatening to do grievous bodily harm to the girl's father.

As the father went outside to get wood for his fire on July 19 last year, he found Johnston lurking near the sleepout and chased him, grabbing him as he tried to scale a fence.

The father put Johnston in an armlock and then applied a choker hold. But when Johnston produced a garden fork and threatened him, the father let go.

A police dog tracked Johnston through the neighbourhood and located him.

The trial was told Johnston had two rape convictions and more than two dozen for burglary.