A killer was motivated by male entitlement, jealousy and rage when he strangled his ex-girlfriend and then burnt her remains in remote Victorian bushland, a prosecutor has told a court.

Hannah McGuire had the right to leave Lachlan Young after months of abusive and controlling behaviour, crown prosecutor Kristie Churchill told the Victorian supreme court in Ballarat on Tuesday.

Instead of accepting the relationship was over, Young murdered the 23-year-old woman because he could not stand to see her living a life without him.

“He attacked and killed Ms McGuire in her own home,” Churchill said. “Her final moments must have been filled with terror.”

Sign up: AU Breaking News email

Young, 23, initially denied he murdered McGuire, arguing her April 2024 death was a spontaneous incident.

But after eight days of evidence at trial, he admitted he strangled her in the bathroom of their Sebastopol home about 2.30am on 5 April.

He then shoved her body into the footwell of her Mitsubishi Triton, drove it to remote bushland in Scarsdale and set the vehicle alight.

As he left the scene, Young used McGuire’s phone to send messages to her mother, Debbie, claiming she was going to take her life.

He then transferred $2,000 from McGuire’s bank account to her mother and $5,000 to himself.

Hannah McGuire, 23, had taken out intervention orders against Lachlan Young before he killed her, the court heard. Photograph: GoFundMe

Young’s barrister, Glenn Casement, has said his client’s actions after the murder were callous, but argued they were amateurish and a sign of his immaturity.

Churchill rejected that submission on Tuesday.

“It cannot simply be explained by his youth or lack of education,” she told the court. “They are the actions of someone who is cold, calculated and remorseless.”

She pointed to the grief of McGuire’s family, friends and colleagues, saying Young had also robbed them of the chance to say a proper goodbye.

“He disregarded her dignity while also eradicating any evidence,” Churchill said. “He engaged in a series of acts to avoid responsibility and attempted to lay the blame of Hannah McGuire’s death at her own feet.”

The prosecutor outlined the concerning rates of family violence in Victoria, stating such crimes warranted significant condemnation and punishment.

She outlined the abuse McGuire experienced in the lead-up to her death and the fact there was an active intervention order in place at the time.

Churchill called on Justice James Elliott to impose a lengthy prison sentence, arguing Young’s moral culpability was high.

“He was motivated by male entitlement, jealousy and rage,” she said.

Casement told the court Young’s age needed to be considered in sentencing, as well as his troubled upbringing, substance abuse issues and poor mental health.

He conceded the only evidence of remorse was his client’s guilty plea and a note from Young’s sister in her letter of reference.

McGuire’s parents, Debbie and Glenn, wiped away tears as Elliott held a minute’s silence for their daughter during the plea hearing.

Young kept his head down during the moment of reflection.

Elliott did not set down a day for the sentencing hearing, instead indicating he would need some time to consider all of the material.

Young was remanded in custody.

• In Australia, the crisis support service Lifeline is on 13 11 14 and the national family violence counselling service is on 1800 737 732. In the UK, Samaritans can be contacted on freephone 116 123 and the domestic abuse helpline is 0808 2000 247. In the US, the suicide prevention lifeline is 988 and the domestic violence hotline is 1-800-799-SAFE (7233). Other international helplines can be found via www.befrienders.org