Jemma Lilley (l) and Trudi Lenon who were convicted of killing an autistic teenager for the thrill of it
Jemma Lilley (l) and Trudi Lenon were sentenced to life imprisonment on 28 February. Supplied

A British woman who stabbed an autistic teenager to death in Australia has been jailed for life.

Jemma Lilley murdered 18-year-old Aaron Pajich at her home in Perth, Western Australia, with the help of her housemate Judi Lenon in June 2016.

They approached the teenager from behind as he played video games and used a wire to strangle him, before stabbing him three times.

Pajich's body was found buried under tiles in Lilley's garden.

On Wednesday (28 February), the Supreme Court of Western Australia sentenced the pair to life imprisonment, with a minimum sentence of 28 years.

The court heard how 26-year-old Lilley, from Lincolnshire, had an "obsession with serial killers" and had included "murder" on her bucket list.

Once she had ticked murder off her bucket list, she was so "full of herself and euphoric" that she boasted about the killing to a colleague, prosecutor James McTaggart told the court.

Lilley had also written a book about a serial killer called SOS. She started to assume the identity of the killer in daily life, jurors heard.

After Lilley's conviction, her stepmother, Nina Lilley, told The Times: "The book was a big problem with me. At the beginning I was, 'fair enough you want to write a horror story', but I didn't like the contents of it.

"She had always had an obsession with serial killers but she said it was a way of venting her frustration of what happened when she was a child," she said.

Pajich's mother described Lilley and Lenon as "disgusting animals" and said they should never be released.

"He was my precious little boy, he was my first-born. He was full of life," she said. "They deserve everything they get for what they've done, they've taken an innocent boy from his loved ones."

Aaron Pajich, 18, who was killed after entering the Perth home of Jemma Lilley and Trudi Lenon in June 2016
Autistic teenager Aaron Pajich was lured to his death in June 2016. Facebook