Awatea Crofts says his son Teancum Vernon Peterson-Crofts: "Just spiralled and spiralled and continued to spiral down".
Michelle Peterson's son Teancum Peterson-Crofts, 19, stands accused murdering his mother and two siblings.
Teancum Petersen-Crofts was charged with three counts of murder yesterday after three people were found killed in a horrifying attack.
WAtoday reports Teancum Vernon Petersen-Crofts was at the emergency department of Perth's St John of God Midland public hospital on Saturday evening.
1 NEWS has been told the 19-year-old male charged with the murders is related to the victims.