Two Perth women who lured 18-year-old Aaron Pajich, the friend of one of their sons, to a house and stabbed him to death in a thrill kill have been jailed for life.
Jemma Victoria Lilley (26), the supermarket shelf stacker who desperately wanted to be a serial killer, and her housemate Trudi Clare Lenon (44), the mother of three involved in a dominant submissive relationship with her, were described as killers without empathy who planned the murder for their pleasure.
The two women did not say anything but looked shocked after the sentences were read out by WA Supreme Court Justice Stephen Hall.
The courtroom was packed with Aaron's family members and supporters and former supermarket colleagues of Lilley.
The case shocked Perth last year.
The two had no criminal records and had lured Aaron, who showed signs of Asperger syndrome and was trusting because he was friends with Lenon's young son, with no motive other than the pleasure of killing him.
The pair were seen on their own security camera in the backyard of their Perth home walking into the house with Aaron on the day of his disappearance and later locking a back gate to trap him.
When his body was later found in their backyard beneath hastily laid concrete and tiles, a post-mortem examination concluded he had died from two knife wounds to his chest and neck after a wire garrote had likely broken on his neck.
The pain would have been significant, said state prosecutor James MacTaggart.
The pair had not shown the "slightest regard or remorse" for what they had done, Justice Hall said.
Text messages after the murder show the women continued their role-playing habit and described feeling "empowered" - Lilley as a serial killer character called SOS, inspired by the US murderer David Berkowitz, and Lenon by her submissive bondage name Corvina.
"Your malicious pleasure at public appeals was clear when Mr Pajich was missing," Justice Hall said.
"The offence is morally repugnant ... all right-thinking people would have feelings of horror and revulsion.
"It was a planned and premeditated killing over weeks, including how it would be carried out, the body disposed of and cleaned up.
"It was a pitiless pursuit of your desire to kill for your own pleasure."
While Lilley had spoken more to acquaintances of her desire to kill before the age of 25, Justice Hall said he held them equally responsible, with Lenon having organised the victim.
Psychiatric and psychological reports showed a disturbing lack of empathy in both women, who came from troubled, abusive backgrounds, with Lilley in particular described as a damaged and disturbed woman who continued to deny the murder and fell slightly short of the criteria of psychopathy.
A jury found the pair guilty of murder last October.
