The B.C. father who admitted to killing his three young children will face cross examination at his trial today.

Allan Schoenborn openly wept yesterday while describing how he took the lives of ten-year-old Kaitlynne, eight-year-old Cordon and five-year-old Max.

The 41-year-old testified he swung a cleaver at the neck of his daughter and that she struggled and pleaded until her death.

He said Kaitlynne cried out "I'm sorry daddy, I'm sorry," before her death.

The father then told the court how he suffocated his two boys, using a pillow with Cordon, and putting a yellow plastic bag around Max's head.

He said he then wrote "forever young" on the walls with soy sauce, and "gone to Neverland" in blood on pillows.

Schoenborn said he attempted suicide unsuccessfully afterwards, and then ran into the mountains with his dog. He was discovered by a hunter 10 days later, severely exhausted and dehydrated, and suffering self-inflicted injuries.

He told the court they'd all had a nice day flying kites together, but he became convinced Max was being molested, and he had no choice but to kill the children.

His defence contends he should not be found criminally responsible for the three counts of first-degree murder because his actions were the result of a severe mental disorder.

Revenge killings?

The Crown, who began questioning him late Wednesday, will continue with their own theory today -- that he killed to exact revenge on the children's mother, Darcie Clarke.

Schoenborn told the judge he spoke with Clarke several times by phone and in person on the two days before their deaths in hopes of working on their relationship problems.

Clarke earlier testified she was staying at her mother's that weekend and had left the children in his care while she tried to alleviate her own depression.

He testified that in the days prior to the murders he believed there was a conspiracy to keep his family apart being perpetrated by a government ministry, the police and the school board.

Schoenborn recounted a history of being admitted to psychiatric wards of hospitals, including an incident when Kaitlynne was 16 months old.

Fearing she'd been drugged, Schoenborn crashed his truck while racing her to hospital. Even after it was confirmed she was well, he pushed for further tests until he himself was admitted to hospital.

With files from The Canadian Press