LOUISVILLE, Ky. (WDRB) -- She was raped, stalked, then shot and killed on her birthday.  Mary Byron's disturbing murder exposed a fatal flaw in our justice system.

But now her parents have reason to celebrate due to calls such as this: "This offender was released from custody on Dec 4th 2013."

The call that seems so common today grew from tragedy 20 years ago this week.  Mary Byron's father John explains how it all began: "We were decorating the Christmas tree and waiting for her to get home and when she didn't show up, I took the path I thought she would be driving and I drove in on it over at the Mall."

Mary Byron was shot six times at point-blank range.  Her ex-boyfriend Donavon Harris was convicted of pulling the trigger.  He was waiting for her to leave work at the J.C. Penny hair salon after he was released from jail earlier in the day, charged with her rape.

No one told Mary he was free.

Her mother Mary's reaction was, "Shock, awe, what can I say?"  That shock led Byron's parents to champion the Victim Information and Notification Everyday (VINE) system.  It calls crime victims anytime there's a change in offenders' status.

As Marcia Roth of the Mary Byron Project explains, "There was no ability for anyone to notify victims anywhere in the country before this happened."

Wednesday morning, the Byrons joined the people who have been in the fight with them for two decades.  Pat Byron says, "It gave us some place to put our energies and not become bitter and angry and make something good out of something bad."

Nine million VINE notifications were sent out in 2012 alone.  The system that started in Louisville is now in place in 47 states.

Michael Davis of Appriss Inc. says, "If even one-tenth of one-tenth of one percent of them are like Mary, and that call is the difference of survival, then there are tens of thousands of crime victims alive because of what came out of that system. So the Byrons, I think, celebrate by thinking of the thousands of other families who have avoided the tragedy that they couldn't."

Pat Byron now speaks to young girls about dating violence.  The Mary Byron Foundation launched in 2000. It educates employers on how to identify workplace violence, and the Byrons plan to lobby in Frankfort in January.

Pat Byron explains, "Dating violence is domestic violence, but domestic violence under the current law is, you have to be living with, married with, or have a child in common, and if you don't meet that criteria you can't get a civil protection."

Davis says, "They're the perfect example of taking something that could destroy your life and turning it into a motivator to go change the world."

A parent never gets over the death of a child.  But Pat and John Byron have become the definition of how to get through it, Pay Bryon saying, "I think you should celebrate. If you walk around with a long puss all your life, no one is going to want to have anything to do with you."

Mary Byron would have been 41 years old on Friday.  Her parents will mark the occasion attending Mass and visiting her gravesite.  Donovan Harris is serving a life sentence in prison for murder.

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