Inmate admits to boiling water attack on Aaron Pajich's murderer

A prisoner has admitted to attacking one of WA's most high-profile murderers, Trudi Lenon, in jail.

Nyiltjiri Naalina Forrest today pleaded guilty to two charges of an act or omission causing bodily harm.

The court heard the 35-year-old burned Trudi Lenon with boiling water, because she was "disgusted" by the callous thrill killing of autistic teenager Aaron Pajich.

RELATED: Thrill killers jailed for life for murder of autistic teenager Aaron Pajich

Convicted child killer Lenon was waiting in line to receive medication at Bandyup Women's Prison on New Year's Day when she was attacked.

Today, the court heard Forrest initially planned to pour just a cup over Lennon but instead grabbed a two-litre container, spilling the contents over her back.

Lenon was treated in the intensive care at Fiona Stanley Hospital for burns to 21 percent of her body.

The 44-year-old is currently serving a minimum 28-year jail sentence over the brutal and calculated murder of autistic teenager Mr Pajich. 

Lennon and accomplice Jemma Lilley were jailed for life in February for murdering the 18-year-old to their Orelia home in 2016.

The women used Mr Pajich's love of computer games to lure him to Rockingham Shopping centre, and then to their Orelia home.

There, he was stabbed and strangled and his body buried in the backyard, under a crude concrete slab.

The murder was driven by an obsession with serial killers, knives, and sexual fetishes.

Lenon's attacker Forrest today applied for bail, but it was refused by a magistrate.

The 35-year-old will be sentenced in August.