The two women, who murdered Aaron Pajich in a 'thrill kill' at a home in Perth's south, have been sentenced to life behind bars.
Perth Supreme Court Justice Stephen Hall handed Trudi Lennon, 43, and Jemma Lilley, 26, a minimum of 28 years in prison for the June 2016 stabbing.
Mr Pajich, who had autism, was lured to a home in Orelia where he was fatally stabbed and buried in the backyard.
Police later found his body under a freshly laid concrete slab.
Both women denied responsibility but were convicted after a five week trial last year.
During the trial, it was revealed Ms Lilley had an obsession with serial killers and expressed a desire to carry out a murder herself.
Ms Lilley has maintained her innocence and intends to lodge an appeal.