Imagine living just blocks away from a woman who was once convicted of murdering your son

That's the new reality for Surrey, B.C., mother Sandra Martins-Toner after a judge threw out Katherine Quinn's conviction and let her out on bail.

Four years ago, Quinn was convicted of murder for ordering her boyfriend Robert Forslund to kill16-year-old Matthew Martins at a SkyTrain station.

Both Quinn and Forslund were sentenced to life in prison. But last month, Quinn's conviction was overturned.

It all came down to a beer bottle. Crown contends that Katherine Quinn handed it to her boyfriend to slash Matthew Martins' throat.

But the appeal judge ruled there was no evidence to support that this is what happened. The Appeal court also decided that the trial judge erred in his instructions to the jury.

It was enough to throw out the conviction. And today Quinn was granted bail pending a new trial. Quinn will remain under house arrest at her parents' apartment, just blocks from the Martins' home.

"It makes us very upset and my wife very fearful that we are going to run into her at our grocery store somewhere,'' said David Toner, Matthew's stepfather.

"What I want everyone to know today is that not only has the criminal justice system failed my beautiful child; they have failed all of you and all Canadians,'' said Martins-Toner.

"There is nothing there to protect you, so don't ever have any sort of faith or hope that the justice system is there to defend your child who you have lost to a vicious and callous crime,'' she said.

Quinn is only allowed out only for court and medical appointments. Her defense lawyer argued the house arrest is actually worse than prison.

"I think that's ridiculous,'' said Matthew's stepdad. "House arrest cannot be viewed by anyone with any common sense as worse than a prison cell.''

"How can it be worse when she is entitled to see her children,'' added Martins-Toner.

"How can that possibly be worse when I don't even get to spend a moment with my child."

Martins-Toner left court defeated, hoping that the next time she sees Katherine Quinn is in court at the re-trial.

With a report by CTV British Columbia's Shannon Paterson