A man charged with fatally stabbing an Abbotsford, B.C. teenager and seriously wounding another is currently not fit to stand trial, a judge ruled Friday.

Justice Heather Holmes sided with the defence attorney representing Gabriel Klein, who said his client would be unable to meaningfully participate in the trial due to his ongoing psychosis.

The trial was scheduled to begin May 7. Instead, Klein will return to the hospital where he's been treated four times in the last 17 months.

Those hoping for swift justice will have to keep waiting, but the case is not closed.

Klein will continue treatment at Colony Farm Forensic Psychiatric Hospital in Coquitlam and be held until it is determined that he is well enough to be tried. A review board will hold a hearing within 90 days to determine whether he's fit enough for trial.

If the board determines he is fit, he'll return to court. If he remains unfit, his status will be reviewed at least every two years.

Holmes' decision was made following a days-long hearing in New Westminster Supreme Court which included testimony from the psychiatrist who conducted Klein's assessment.

Dr. Marcel Hediger told the court Wednesday that Klein told the doctor he once killed an individual and seriously injured another.

Hediger said he believes Klein has schizophrenia and suffers from paranoid delusions.

During Klein's stay at the Surrey Pretrial Services Centre, he believed he had been poisoned and that his life was at risk, Hediger told the court.

Klein hears voices and believes the CIA is following him through surveillance cameras, and has refused to take his medication, Hediger said.

Hediger said that when Klein was in a clinical setting, he was able to understand he was facing charges, show a rough understanding of the trial process and understand the potential to be sentenced if convicted. The ability to understand his situation could meet the legal requirements of being fit for trial, the doctor said.

However, the psychiatrist added that Klein's delusions could impact his understanding of what's happening in court. His condition varies, and the added stress of the court room could bring out his psychosis, the doctor said.

He is also undergoing a change in medication that could impact his mental state for the next six weeks.

Klein's lawyer argued his current condition made him unfit to stand trial, and said Friday he expected the trial would be delayed.

"Mr. Klein is schizophrenic. He suffers from paranoid delusions. His psychosis is currently very active and likely to interfere with his ability to keep track of the proceedings in court," Martin Peters said.

Peters said there is a provision in the criminal code where someone can be found permanently unfit and the charge is stayed, but Klein wouldn't be let out if that happened.

"He's not going to go anywhere unless at some distant point in the future the review board finds he does not pose a risk to the public," he said.

Peters added that he knows Friday's ruling might be upsetting for the victims' loved ones, but putting a mentally ill man on trial isn't the answer.

Ahead of the decision, the Crown asked the judge to weigh whether it was more or less likely that he'd meet the criteria for being unfit at the time of the trial.

"If the court accepts evidence establishing on a balance of probabilities that there will be times during the trial when the accused is likely fit, the Crown is essentially not opposed to a finding that he is not fit," Rob Macgowan said Thursday.

Klein has been charged with second-degree murder for his alleged role in the death of 13-year-old Letisha Reimer, who was stabbed near the entrance of Abbotsford Senior Secondary School in November 2016.

He is also charged with one count of aggravated assault for an attack on Reimer's 14-year-old friend, who survived. He was 21 at the time of the stabbings.

Police said the man who walked into the school with a knife was shoeless at the time. A suspect was confronted and restrained by staff until officers arrived.

None of the allegations have been proven in court.

With files from CTV Vancouver's Shannon Paterson, Jon Woodward and The Canadian Press