A teenager accused of murdering a mother and two of her children at their Ellenbrook home has been sent to a secure psychiatric facility, with a magistrate expressing concern for his mental health.

Teancum Vernon Petersen-Crofts, 19, faced the Midland Magistrate’s Court this morning charged with killing a 48-year-old woman, her eight-year-old son and 15-year-old daughter early yesterday.

Mr Petersen-Crofts lived at the Brixton Crescent home and it is understood he is related to those killed, but their exact relationship is still unclear.

He appeared in the dock wearing a grey jumper and was handcuffed to one of the two security guards with him.

In what was an unusual scene, Mr Petersen-Crofts interrupted Magistrate Greg Smith as he began to tell him that he was facing three counts of murder.

He said a man, whose name was inaudible, was a “criminal” and “he did it”.

“He wanted to take me out bush, he did it,” he said.

“I went home, I came back to my family.” At this point, Mr Smith told Mr Petersen-Crofts that he was not required to say anything, but he continued.

“I need to, because mamma is with me,” he said.

“I was painting a picture of Jesus … he punched me so hard it’s not funny.

“I left because I had to, because I was so scared he was going to kill me.

“Mamma told me to save myself.”

Then, Mr Petersen-Crofts turned to one of the security guards and told him that he looked like a serial killer.

“You look like a serial killer and you’re a security guard,” he said.

Mr Smith said there were concerns for Mr Petersen-Crofts’ mental health and remanded him to the Frankland Centre, a maximum-security facility at Graylands hospital, for one week on a hospital order.

The charges were not formally read to Mr Petersen-Crofts.

He will appear in the Stirling Gardens Magistrate’s Court on Monday.

A friend of the deceased mother, Toni Ata, has set up a fundraising page to help cover the costs of the three funerals.

Ms Ata described her friend as “kind, happy” and who “loved her kids, all of them unconditionally.”

“At times in her life she was rough, she was flawed but we all are, no one is perfect…,” she wrote.

At 11am, more than $4600 of a $15,000 target had been raised, with donations from 140 people.