Updated

A British woman who had committing murder on her "bucket list" and had an "obsession" with serial killers was sentenced to prison on Wednesday for the brutal killing of an autistic teenager in Australia.

Jemma Lilley, 26, strangled, stabbed and buried 18-year-old Aaron Pajich at her home in Perth on June 13, 2016, according to prosecutors.

The 26-year-old was sentenced to life in prison with a minimum term of 28 years, the same sentence given to her housemate, Trudi Lenon, at the Supreme Court of Western Australia, according to Sky News.

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Aaron Pajich, right, was strangled and stabbed to death by Jemma Lilley, left, and Trudi Lenon in 2016. (Supreme Court of Western Australia/Western Australia Police)

Prosecutor James McTaggart told jurors Lilley had spoken of wanting to kill someone before she turned 25, and after the slaying was "full of herself and euphoric" while boasting to a coworker. Prosecutors said she also idolized horror movies, including the character Freddy Krueger from the “A Nightmare on Elm Street” series, according to News.com.au.

Lilley and Lenon met through a friend and became close, eventually moving in together two months before the killing, according to the BBC. Prosecutors said the pair exchanged homicidal fantasies until Pajich's killing, and had bought various supplies such as a circular saw and 100 liters of hydrochloric acid to help dispose of the body, the BBC reported.

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A set of knives and a bone saw recovered from the house where Jemma Lilley and Trudi Lenon lived. (Supreme Court of Western Australia)

Pajich, who had autism, was lured to his death in June 2016, with both defendants blaming each other for the killing. Lenon said during the trial that Lilley approached the teenager from behind as he installed games on her computer, strangled him until the wire broke and then stabbed him three times, Sky News reported.

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Knives and horror film memorabilia are seen in the home where Aaron Pajich was killed in June 2016. (Supreme Court of Western Australia)

Prosecutors said during the trial that Lilley left incriminating messages to her "obsequious and sycophantic" follower Lenon hours after the killing, saying she was feeling things she had "not felt before," according to Sky News.

WOMAN KILLED AUTISTIC TEEN TO CHECK OFF MURDER FROM 'BUCKET LIST,' PROSECUTORS SAY

Jurors were also told Lilley had written a book about a serial killer, called "SOS," and went on to assume the identity of the main character.

“The book was a big problem with me," Lilley’s stepmother, Nina Lilley, 48, told The Times. "At the beginning I thought, ‘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,"

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Pajich's body was found underneath these tiles in the back garden of the home where Jemma Lilley and Trudi Lenon lived. (Supreme Court of Western Australia)

After the pair was sentenced, the victim's mother told reporters she was heartbroken and would have to deal with what happened to her son for a lifetime.

"He was my precious little boy, he was my first-born. He was full of life," Sharon Pajich said, adding the pair were "disgusting animals" and should never be released. "They deserve everything they get for what they've done. They've taken an innocent boy from his loved ones."