Family members of a 16-year-old boy who was killed on July 1, 2005, were devastated after one of the accused was found not guilty of second degree murder on Monday.

"Justice has not been done. Justice has failed my child, and it will fail many more children," said Sandra Martins-Toner whose son Matthew Martins died after he was severely beaten and his throat was slashed at the Surrey Central Skytrain station.

Katherine Quinn and her boyfriend, Robert Forslund, were convicted of the killing in 2007. While Forslund is serving a life sentence with no parole for 17 years, a new trial was called for Quinn.

During the second trial the court heard from several key witnesses and the Crown tried to prove that Quinn ordered her boyfriend to kill Matthew after what began as an attempted robbery.

B.C. Supreme Court Justice Wendy Baker found their testimony unreliable.

Mother Sandra Martins-Toner left the courtroom before the judge had finished giving the verdict.

"I just couldn't hear any more. I'd had enough. Two and half hours of sitting there listening to her tell us that everything we've been told for the past five years is a lie, and that Quinn is innocent. How can a parent want to sit there and listen to that?" she said.

"It just doesn't make any sense to me. How can so many people, you know, how can so many people have heard something and yet she's found not guilty. It makes no sense," she said.

The deceased's brother Brayden Toner was also present.

"I miss my brother a lot. Nothing can replace him. I just wanted justice, for all of us. I don't know what else to say," he said.

Matthew's step-father David Toner feels let down by the legal system.

"I think it confirms that change is needed, that the justice system as it works is so caught up in procedure and technicality," he said.

The family can sue Katherine Quinn in civil court, but that would mean going through another trial -- one that they're not sure they can win.

"There's no monetary value that could ever replace my child. There's no money in the world that could ever replace such a beautiful young man," Sandra said,

With a report from CTV British Columbia's St. John Alexander and with files from The Canadian Press