A 26-year-old British woman who was obsessed with serial killers and fantasised about a “screaming pleading victim” has been sentenced to life in prison – along with her Australian housemate – over the brutal “thrill killing” of an 18-year-old in Perth.

Jemma Lilley and Trudi Lenon, a 44-year-old mother of three and well-known “submissive” in the local bondage scene, showed no emotion as a court in Western Australia sentenced them for the “morally repugnant” murder of Aaron Pajich, whom they lured to their home, executed and buried under fresh concrete.

Justice Stephen Hall said the murder in 2016 was committed for the “pitiless pursuit of your own desires ... you killed for your own pleasure.”

The court heard that Lilley, who moved to Perth from Stamford, Lincolnshire, in 2010 and was working as a night manager in a supermarket, had been obsessed with murder for much of her life and once told a friend she wanted to kill someone before the age of 25.

Once she had ticked off murder from her "bucket list" she was so "full of herself and euphoric" that she could not help boasting to a work colleague, prosecutor James McTaggart told the court during a four-week trial last year.