A wheelchair-bound man who stabbed his friend to death in a frenzied attack told his carer he needed to have sex with her 'to save the animals' during a bizarre drug-induced meltdown, a court has heard. 

Autumn Baker, 40, of Darley - about 60km northwest of Melbourne - was murdered by Mark Graham Ludbrook on August 3, 2023.

A Supreme Court of Victoria jury found him guilty of the crime in February after the jury in his first trial failed to come up with a verdict.

On Thursday, Ludbrook, 54, was sentenced to 19 years in prison with a 14-year non-parole period - he has already served 678 days behind bars. 

In sentencing, Justice James Gorton outlined bizarre new details of the brutal crime. 

The court heard Ludbrook’s behaviour turned wildly erratic after he took a double dose of an illegal ketamine-like drug called PCE at his Hoppers Crossing home, west of Melbourne, on August 3, 2023.

'You told (your carer) that you needed to sleep with her to save the animals, which she rebuffed,' Justice Gorton said. 

'You then removed your pants and stood at the end of the bed ... You asked (her) to give you high fives or a high tenner to say, "Hallelujah when your hands connected."'

In another grotesque moment, Ludbrook was seen spitting on cash and smearing it over his naked body. 

'She saw you spitting on banknotes, including the $50 notes she’d bought to you earlier, and rubbing them over your body while calling out amounts of money and saying that you would save 10,000 souls,' Justice Gorton said.

The killer also wandered into the backyard and spoke to flowers as his carer filmed the bizarre conversation on her phone.

'You walked through the house and into the backyard, where you spoke to a daisy bush,' the judge said.

The carer had described Ludbrook acting 'like a vibrant, expressive game show host' while rambling about saving animals and thousands of people as he thanked colours and spoke of paintings representing him and his ex-partner.

The horrifying episode escalated when Ms Baker arrived at the house out of concern for Ludbrook, who had been her friend.

Ludbrook, naked, grabbed a steak knife from the kitchen, stabbed himself in the abdomen, then turned on the unarmed mother-of-two as she tried to help him. 

Justice Gorton described the horrific attack in bloody detail as Ms Baker's family watched on.  

The court heard Ms Baker was stabbed repeatedly in the chest and face around her eyes and left to die on the bedroom floor. 

She had suffered defensive cuts to her hands as she fought for her life.

The court heard Ludbrook blamed his carer for his evil actions as he continued to knife his defenceless victim. 

‘Now you can be clean,’ he yelled at her. 

'Why won’t you sleep with me, see what you’ve done?’

In sentencing, Justice Gorton said he accepted Ludbrook's use of the synthetic drug reduced his ability to make sound decisions. 

Ludbrook suffered from a rare condition known as Transverse Myelitis - a neurological disorder caused by inflammation of the spinal cord - and had supposedly been confined to a wheelchair leading up to the murder.

But on the day of the attack, Ludbrook's carer noted he was up and about on his feet and his behaviour was unusual.

'In the unusual circumstances of this case, the fact that as a result of your ingestion of PCE, your actions took place at a time when you had little ability to tell right from wrong significantly moderates your moral culpability for this crime,' Justice Gorton said. 

'I do, however, accept ... your ability to reason about whether your conduct was wrong, your capacity for moral reasoning was severely impaired.'

Ms Baker had made a name for herself during Victoria's record-breaking Covid-19 lockdowns, which she vehemently opposed.

Videos captured from the time show Ms Baker participated in numerous protests across Victoria against mandatory vaccinations.

At that time, Victorians who refused to receive the Covid-19 vaccinations at least three times were being sacked, with the remainder of the state facing endless lockdowns if they did not comply.

On January 15, 2022, Ms Baker took control of a microphone at a large protest in support of tennis ace Novak Djokovic.

Djokovic had been detained and then deported from Australia after taking a stance against the Covid jab.

Standing before the mob of frustrated Melburnians, Ms Baker chanted: 'The people united will never be defeated', 'Hey Pfizer leave our kids alone', 'Hands off our kids they are not your Guinea Pigs', 'Free Victoria' and 'No more vax pass.'

The court heard Ms Baker had shown compassion for her killer leading all the way up to the moment he started knifing her.