Police believe they have found the human remains of a killer who sparked a major police hunt after fleeing a Claremont psychiatric hostel in 2014.
Samuel Mark Walsh was sentenced to be detained in a mental health facility after he was found to have killed his mother Patricia Lynette Wright during a psychotic episode in Kalgoorlie in 2005.
He had lived at Romily House in Claremont for four years before he went missing in October 2014 after telling staff he was going to attend a church service.
His disappearance sparked a massive police hunt and caused questions to be raised about security measures at the mental health facility.
Police on Wednesday discovered Mr Walsh's likely remains inside a car in bushland near the Karalee Rocks Pumping Station in Yellowdine.
"The remains are believed to be those of 38-year-old Samuel Mark Walsh, who was reported missing from a care facility in Claremont on 5 October 2014," a police spokeswoman said.
"Formal identification is yet to take place.
"There is no evidence of criminality and police will now prepare a report for the Coroner."
Mr Walsh, formerly known as Enoch Samuel Wright, was acquitted of his mother's murder in 2007, after Supreme Court Justice Geoffrey Miller ruled he was not criminally responsible for his actions.
He spent three years at a secure psychiatric hospital on a mandatory custody order before being granted supervised release by the Mentally Impaired Accused Review Board in 2008.
The "leave of absence order" meant he could leave Graylands Hospital and live independently in supervised accommodation at Romily House.
At the time Mr Walsh went missing, fears were held for his state of mind because he had not had medication needed to manage his schizophrenia.
He was understood to have left the care facility in his own car, a 1998 silver Hyundai Excel – the same car he was found deceased in on Wednesday.
His remains were found in bushland west of Coolgardie.
For anyone seeking crisis support or needing help, contact Lifeline: 13 11 14 or lifeline.org.au