The father of three murdered children admitted in a secretly recorded jail-house interview that he killed the children, but he assured their mother they weren't tortured before they died.

The children's mother testified Tuesday, the first time she's spoken publicly about the murders, that her former partner appeared increasingly mentally ill in the months before the murders, but refused to see a doctor.

Darcie Clarke testified her partner, Allan Schoenborn, confessed two months after the bodies of five-year-old Cordon, eight-year-old Max and 10-year-old Kaitlynne.

Schoenborn thought he was telling only his former common-law wife, but she had agreed to tape the conversation for police.

She met with him at the Kamloops Regional Correctional Centre and spoke on a phone to him, face-to-face with glass separating the two.

The audio of the conversation was played Tuesday in B.C. Supreme Court.

Schoenborn told Clarke he killed the children to protect them.

"I thought they were being molested," he explained.

When Clarke asked why he couldn't have just walked away, he replied that he couldn't because they were in trouble.

"I didn't torture anybody Darcie," his voice raised as she sobbed in the background.

"I thought it was going to go quick," he said referring to the children's deaths. "It didn't go quick. It's not like I knew what I was doing."

As their conversation ended, he told her "Don't be so angry. You gotta get that out."

Clarke, a petite, 38-year-old blonde dressed in a black suit, was composed through most her testimony.

But she sobbed uncontrollably as she spoke of walking into the family's trailer home to find her children dead.

When she arrived home at about 2 p.m. she saw her boys Cordon and Max lying on the couch and thought it was odd that both would be napping.

"I looked closer. They weren't alive."

Clarke wept as she described finding Kaitlynne.

"I went to her bedroom and she was all tucked up in a blanket. There was a huge gash from her ear to her mouth and a cut on her wrist."

Clarke said she kept repeating to herself that it wasn't happening, it couldn't be real.

"I started running around screaming, 'no, no, no."'

Video of the murder scene has already been shown during the trial, which is being heard by judge alone.

The RCMP tape showed the two boys cuddled on the couch and a blood-spattered murder scene. The trial has heard that the boys were either smothered or suffocated, while Kaitlynne was stabbed numerous times.

The confession was one of three interactions Clarke had with Schoenborn after her children were killed.

He spoke with her on the phone, but said he didn't want to explain what happened because the conversation may be taped.

Sounding clear and coherent, he called her Darce, and kept up a stilted conversation with her.

"I'm glad you're OK," he said before hanging up.

Schoenborn then sent her a long, rambling letter about how he survived and attempted to kill himself in the woods in the 10 days after the children were killed.

He opens the letter, dated June 12, 2008, greeting Clarke as "Beautiful."

Schoenborn informs her within the first few sentences that one of his toes had fallen off from frostbite.

"Hey, it ain't no biggie, just a little iggy. I'm just a little baby toe," he wrote, apparently referring to the lyrics of a song.

In the letter, which Clarke read to the courtroom, Schoenborn made several references to suicide.

"My only tickets now are to jump in front of a moving truck or starvation," he wrote to her. "I was going with them."

He said he was trying "to finish my quest towards the children."

In the June 2008 recording, Schoenborn reassured Clarke that he didn't torture the children.

"I thought it was going to go quick. It didn't go quick. It's not like I knew what I was doing," he said on the recording.

Clarke agreed to work with police and recorded conversations both on the phone and face-to-face at the jail.

Clarke testified that the day before she found her three children dead in her Merritt, B.C., home, she told Schoenborn that their relationship was over.

Clarke said she had a long conversation with him on her front lawn on April 5, and told him she had gone to the doctor to get some anti-depressants. She testified that Schoenborn then asked her for one of the pills and she gave him one.

Two months after the murders, Clarke said he sent her a letter detailing how he tried to kill himself several times after the murders, and before he was found hiding in the woods.

She said he told her that he was "longing" to be with the children.

Schoenborn is on trial on three counts of first-degree murder.

On the wall in the living room, where the boys' bodies were found, "forever young" was written in soya sauce. In the master bedroom, "gone to Neverland" and "forever young" were written on a pillow case in blood.

The Crown has told the judge that Schoenborn's mental state at the time of the murders is the main issue for the trial.

Clarke agreed with a suggestion by Schoenborn's lawyer that her former partner appeared to be growing increasingly mentally ill, testifying that Schoenborn was hearing voices, but refused to go to a doctor because he didn't trust doctors.

Clarke said he was worried it would be like "One Flew Over the Cuckoo's Nest. He might be lobotomized."

She testified Schoenborn was constantly accused her of having an affair, behaviour she called jealousy but which Schoenborn's lawyer, Peter Wilson, described as paranoia.

She said he was diagnosed as paranoid as far back as 1999, but aside from briefly taking medication, he never sought help and never believed he was ill.

"He didn't go see a doctor because he wasn't the problem. I was," she said.