CALGARY -- The families of five young people killed in a stabbing at a house party in Calgary two years ago were given an opportunity to share their grief and anger Tuesday in front of the man who took their loved ones' lives.

In an unusual move in the trial of Matthew de Grood, an agreement was reached to allow members of each family to give a tribute before a verdict.

Such statements are usually given during sentencing, but Justice Eric Macklin agreed it would be appropriate for the families to have their say beforehand. The tributes weren't to have any impact on the judge's final decision.

"He was a good solid young man at the tip of an amazing life and that life was taken away from him," said Bruce Rathwell, whose son Zack was one of the five victims. "I was there when he came into this world and I was there to identify his body as his soul left this world. Hopefully one day we will meet again."

His mother, Ronda-Lee Rathwell, said her 21-year-old son, who was part of a band called Zackariah and the Prophets, lived for his music.

"The thing that fed his soul and made him light up was music. He played every day. I miss that music the most," she said.

Rathwell was killed along with Kaitlin Perras, 23; Lawrence Hong, 27; Josh Hunter, 23; and Jordan Segura, 22. The attack happened at a party being held to mark the end of the school year on April 15, 2014. Police have called it Calgary's worst mass killing.

De Grood, who has pleaded not guilty to five counts of first-degree murder, has admitted he killed the five, but his lawyer has said he plans to argue his client is not criminally responsible.

Court has already heard how de Grood, 24, told police he believed he was killing Medusas and werewolves for the son of God.

Patty Segura told court her son Jordan would help perfect strangers and gave away "hugs for free."

Lawrence Hong was remembered by his brother Miles as a friend to many.

Kaitlin Perras was remembered by her sister Nicky as fearless and as someone who loved dance.

"When Kaiti performed it was like time stood still. She lit up the stage with her grace."

Michaela Hunter said her brother Josh was her best friend, mentor and the one person she could always talk to.

"It's a hole that will never be filled. It makes me extremely sad and scared to be without my big brother."

The trial was adjourned after the emotional morning.

"You've provided the court today ... with a snapshot into what your children and your siblings have meant to you, your families and the community at large," said the judge, who is hearing the case without a jury.

"You've also expressed how your heartbreaking and immeasurable loss has deprived your family, your community and society."

Defence lawyer Allan Fay said allowing the families to speak was unusual, but necessary.

"This is a unique case and it was agreed between myself and the Crown and Justice Macklin that it was important that the families of the victims had the opportunity to speak," said an emotional Fay.

"It's incredibly hard. No one with a heart could be hear that and be unmoved."

De Grood, who sat just metres from the families, looked down at the floor during the tributes and showed little emotion.

Fay was planning to call two psychiatrists to the stand Wednesday.

"I hope people keep that in mind that my client is receiving medications," Fay said. "As a result of those medications he may not react in the way people would hope to see him react."

Follow the live updates from CTV News reporters at the courthouse as they happened: