A West Coast woman is in custody after being found guilty of 11 charges involving sexual offences against her stepson.

The woman, who has interim name suppression, had earlier denied eight charges of unlawful sexual connection with a young person and three of performing an indecent act on a young person, her stepson, who was aged between 12 and 13 when the sexual activity occurred in 2012, not long after he went to live with his father and stepmother.

The woman was in her late 20s at the time.

She was denied bail by Judge Stephen O'Driscoll, who heard the case as a judge alone, when he delivered his decision at the Greymouth District Court yesterday.


Judge O'Driscoll noted in his written decision that he found the complainant, who is now aged 18 and has his name suppressed, a reliable and compelling witness.

"The Crown case is that a relationship formed between the complainant and his stepmother that was sexual and involved various sexual activities," the judge said, noting the Crown told the court the sexual activity occurred in a variety of locations and its frequency ranged from once a week to sometimes twice a day.

"The complainant estimated that he would have had sex with the defendant up to 100 times," the judge's decision said.

"In addition to the evidence of the complainant, the Crown called a number of witnesses to demonstrate that an unhealthy and inappropriate relationship existed between the complainant and the defendant," Judge O'Driscoll said.

The defence case was that the complainant was not a reliable witness, should not be believed and that there was no sexual contact between the two.

The defence submitted that the observations other witnesses made of the relationship were misinterpreted and misconstrued and that there was an innocent explanation for them.

However, Judge O'Driscoll accepted the complainant's evidence that the woman engaged in a number of sexual acts with him over a period of time.

"The explicit detail that the complainant gave relating to the sexual conduct with the defendant and the wide variety of sexual acts described was not something I find originated from (his) imagination," the judge said.

"The defence suggested that the complainant has made up all these sexual scenarios to help his father (win custody of the couple's other children) and to 'get' his stepmother. I reject that submission."

Judge O'Driscoll noted that although the evidence of other witnesses needed to be put into context, there was a "clear pattern or theme (that) provides very strong support for the existence of an inappropriate relationship between ... and the defendant".

In denying the woman bail, the judge said the law made it clear there was no distinction between adult males committing offences against young females, and adult females committing offences against young males.

He said there was a significant age difference between the woman and her stepson and that the offending involved a gross breach of trust.

Although not predetermining sentence, Judge O'Driscoll said imprisonment was "highly likely" and to grant bail would just give the woman false hope.

He asked for a pre-sentence report, a victim impact report and an emotional harm report to be prepared before the woman is sentenced on September 9.

The judge's decision referred to the offending taking place between February and September 2012.

Crown prosecutor Deidre Orchard asked the court to amend the later date to September 2013.

- Greymouth Star