The New Zealand father of a 19-year-old Perth man accused the murdering his mother and two siblings says his son never received appropriate treatment despite a history of mental health issues.
Teancum Vernon Peterson-Crofts had been admitted to mental health facilities on numerous occasions, his father Awatea Crofts told the ABC.
Mr Crofts said his son had been hospitalised in Christchurch early in 2015.
"It was very difficult for him and the mental health staff," Mr Crofts said.
"He just spiralled and spiralled and continued to spiral down, it was a perpetual, continual episode after episode."
Peterson-Crofts appeared in court on Monday charged with the murder of his 48-year-old mother Michelle Petersen, and her two children Rua, 8 and Bella, 15, at their home in the Perth suburb of Ellenbrook.
Petersen and Rua were found dead inside the home while Bella died on the way to hospital.
Mr Crofts said Peterson-Croft’s mother had done everything she could to help her son.
"His mother did everything she could and just in the last days, her last six months, she was still doing everything she could but his condition had blown right out," he told ABC.
"From what I've heard, from other family members, he was rejected for whatever reasons from mental health [services] and Michelle his mum often had the police around."
Where to get help:
Need to Talk? Free call or text 1737 any time to speak to a trained counsellor, for any reason.
Lifeline: 0800 543 354
Suicide Crisis Helpline: 0508 828 865 / 0508 TAUTOKO (24/7). This is a service for people who may be thinking about suicide, or those who are concerned about family or friends.
Depression Helpline: 0800 111 757 (24/7)
Samaritans: 0800 726 666 (24/7)
Youthline: 0800 376 633 (24/7) or free text 234 (8am-12am), or email email@example.com
What's Up: online chat (7pm-10pm) or 0800 WHATSUP / 0800 9428 787 children's helpline (1pm-10pm weekdays, 3pm-10pm weekends)
Kidsline (ages 5-18): 0800 543 754 (24/7)
Rural Support Trust Helpline: 0800 787 254
Healthline: 0800 611 116
Rainbow Youth: (09) 376 4155
If it is an emergency and you feel like you or someone else is at risk, call 111.