A British Columbia father who killed his six children has been found guilty of first-degree murder.

Jay Handel, 46, had always admitted killing them and then setting the family home on fire. But he claimed he was not criminally responsible due to mental disorder. His defence team argued that his deep depression over the demise of his marriage made him incapable of knowing right from wrong.

In the end, the jury didn't buy it. They took only a day to come down with their verdict, which was met by gasps in the courtroom Wednesday night.

"You took the lives of six young, defenceless people,'' B.C. Supreme Court Justice Jim Taylor told Handel. "You have to live with that for the rest of your life."

"This has not been an easy case," Taylor added. "Cases involving children are never easy."

"It's the most difficult case I've been involved in in 23 years," agreed defence lawyer John Green. He added that he thought an appeal was unlikely.

The sentence for first-degree murder is automatic: Life in prison with no chance of parole for at least 25 years.

In a statement read by his lawyer in court, Handel said he loved his children, that he never stopped loving them, and that he's glad the ordeal is over.

During testimony, Handel admitted to killing his children in March 2002 after his estranged wife, Sonya, made it clear she wanted out of the abusive marriage.

Handel described how he drugged, strangled and shot his three daughters and three sons, aged between 11 and two years old. After the family home on Vancouver Island was set on fire, Handel picked up Sonya from a neighbour's house and drove her to the inferno. He then slit his throat in front of her.

In order to convict Handel of first-degree murder, the Crown had to prove that he had had a deliberate plan to kill his children.

The Crown told the court that Handel was clear-headed enough to drug the children before he killed them. A psychiatrist for the Crown argued that Handel was mired in a deep self-absorbed state and was motivated by anger brought on by his wife's rejection.

The defence argued Handel was not guilty by reason of a mental disorder. Dr. Stanley Semrau, who testified on behalf of the defence, said Handel thought he was doing his children a favour by killing them and saving them from a life of "hell on Earth."

Court also heard Handel wrote three letters immediately following the deaths of his children. One was left for his wife, another was mailed to a Quatsino man he accused of having an affair with his wife, and the third letter was mailed to the Handel family doctor in nearby Port Hardy.

In the letter he left for Sonya, Handel told her she was now alone because she refused to come back to the family home and live under his terms.

Sonya Handel, 33, testified early in the trial that she "wanted to spit on (Handel's) corpse" after the murders.

CTV's Sarah Galashan, who was in the court Thursday, reports that as Handel heard the verdict, he shook his head slightly and bowed it.

"I should point out he was wearing his wedding ring, although his wife Sonya was not in the courtroom. She hasn't been since she testified against him.

"He was also wearing long sleeves. That's to cover the bandages on either wrist where he attempted to cut himself two days ago," Galashan says. "We're not sure exactly how serious the suicide attempt that was. He is under a suicide watch right now."

Crown lawyer Derrill Prevett said the jury's decision was gratifying, but he was reminded of the tragedy behind the trial.

"The thing to remember in all of this, and what I remembered every time I opened the file, were six children,'' Prevett told reporters.