Two women convicted of the 'thrill kill' murder of Perth teenager Aaron Pajich are due to be sentenced in the Supreme Court of Western Australia on Wednesday.
Trudi Lennon, 43, and Jemma Lilley, 26, were housemates when they stabbed Mr Pajich to death and buried him underneath a freshly laid concrete slab in their Orelia backyard on June 13, 2016.
Jemma Lilley, left, and Trudi Lenon murdered Aaron Pajich in June 2016.
The "vulnerable" 18-year-old, who had Asperger's syndrome, was targeted and lured to his death by Lenon, who knew the teenager through her 14-year-old son.
Three months prior to his death, Lenon began living with serial-killer obsessed Lilley and had agreed to become her 'submissive' and help her fulfil a desire to claim her first kill.
Lenon, left, buying hydrochloric acid from Bunnings. Lilley, right, the day of Mr Pajich's murder.
Photo: Supreme Court of Western AustraliaCCTV in the days leading up to Mr Pajich's murder showed the women buying large amounts of hydrochloric acid and sealable drums from Bunnings, while text messages between the pair detailed the "screaming, pleading victim" Lilley longed for.
An unsuspecting Mr Pajich, whose Asperger's syndrome led to him having a trusting and innocent nature, received a call from Lenon to meet her at Rockingham shopping centre on the day of his death.
From there, the trio left together and returned to Lilley's Orelia home, where Lenon had also been living with her children.
Police believe Mr Pajich was killed shortly after arriving at the house.
As many as 300 people came out for the touching tribute to 18-year-old Aaron Pajich.
Photo: FacebookAfter several public pleas from his family to help find Mr Pajich, his body was found buried underneath a concrete slab in the home's backyard a week later.
He had been stabbed multiple times, garrotted and had cling film around his face.
Messages between the two women tendered in court.
Photo: Supreme Court of Western AustraliaBoth women denied murdering Mr Pajich and blamed each other, leading to a five week trial in the Supreme Court of Western Australia in October 2017.
Lilley claimed she was unaware Mr Pajich had been killed and that Lenon must have murdered him and concealed the crime while she was taking a three-hour nap in the next room.
The tiling used to hide Mr Pajich's buried body.
Photo: Supreme Court of Western AustraliaLenon however admitted witnessing Lilley stab Mr Pajich to death, claiming she helped conceal the crime out of fear.
She claimed she thought the murderous talk between her and Lilley was just 'role play'.
Aaron Pajich.
Photo: WA PoliceDuring their trial, the jury heard how Lilley was obsessed with serial killers and knives, and had told a friend she wanted to kill someone before she turned 25.
She often referred to herself as SOS, a serial killer character she created for a book she wrote as a teenager in 2007.
Lenon once described Lilley as a "literal psychopath" who was "unnerving but addictive".
A day after Mr Pajich's murder, Lilley sent Lenon a message saying: 'I'm seeing things I haven't seen before and feeling things I haven't felt before', to which Lenon replied: 'You're welcome SOS'.
The pair were convicted of Mr Pajich's murder on November 1, 2017.
Ms Lenon has since been attacked in Bandyup Prison after a fellow inmate allegedly poured a container of boiling water over her.
She sustained serious burns during the incident.
Heather McNeill is a Fairfax Media journalist who returned to the big smoke after a reporting stint in the Pilbara.
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