A teenage girl whose “childish” motivation for revenge led to a man’s violent shotgun murder during a high-speed car chase could be released on parole next year.

Jesse Thompson, 19, was in the back seat of an SUV when he was shot and killed on the streets of Wyong, on the NSW Central Coast on July 3, 2017.

John Paul Evans, 57, was behind the wheel of a ute pursuing the SUV, with his son Keith Evans, 31, in the front passenger seat.

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Both father and son were found guilty of Thompson’s murder in July after a Supreme Court jury retrial.

A 25-year-old woman — who was also in the ute but cannot be legally identified because she was 17 at the time of the death — was sentenced on Wednesday after pleading guilty to murder.

The killing was sparked after one of Thompson’s friends slept with Keith Evans’ girlfriend.

Keith Evans lured the other man to his house at night, where he was attacked by multiple assailants.

In retaliation, two men arrived at the Evans home, making threats and smashing the glass front door.

John Evans, the father, was called and the three offenders piled into the Trident ute.

During the high-speed chase, the ute and the SUV were seen swerving and driving on the wrong side of the road before the weapon was fired.

Thompson was described as a kind, warm, empathetic and friendly man who showed promise, Justice Richard Weinstein said on Wednesday.

“Jesse Thompson was at the start of his life and was senselessly murdered before his potential could be realised — that is the tragedy of this terrible event,” he said.

“We are less of a community because of the loss.”

He sentenced the woman to a maximum period of 14 years and 10 months, backdated to the date of her arrest on July 4, 2017.

Her non-parole period of nine years and three months will expire on October 3, 2026.

Weinstein considered the woman’s prior criminal history of violent offending when handing down this sentence.

However, he also said the woman had a deprived upbringing.

Her mother had been incarcerated, and the woman had been exposed to domestic violence and “warped views” about using violence and revenge to resolve problems.

“I have no doubt that her immaturity was a significant contributing factor in the commission of the offence,” he said.

“In my opinion, the offender’s behaviour was a childish reaction.”

The now-adult woman had made significant strides towards rehabilitation and was unlikely to reoffend, the judge noted.

As well as getting mental health treatment for her bipolar disorder and anxiety, she had commenced a bachelor of psychology while in juvenile prison.

Since being transferred to an adult prison, she still showed promise by connecting with her Aboriginal culture and creating art.

“Much will depend on the resilience of the offender,” Weinstein said.

John and Keith Evans will face a sentence hearing on September 2.

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