A grieving family and two Maryland lawmakers will unveil a bill tomorrow they're calling Laura and Reid's Law. It would allow prosecutors to charge killers with murder in the death of a pregnant woman -- and her unborn child.

The parents of murder victim Laura Wallen have been pushing hard hard for the change.

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Police say her on again, off again boyfriend, Tyler Tessier, killed Wallen, a beloved school teacher, and their yet-to-be-born son, Reid.

But because Reid was just 14 weeks from gestation, and not viable outside the womb, prosecutors under Maryland law could only charge his father with murdering his mother, not him.

"With one bullet, my daughter's boyfriend killed two generations of my family," said Laura Wallen's father Mark.

Laura and Reid's Law would change the language of the Maryland code on fetal homicide, allowing killers to be charged with murder or manslaughter in the death of any unborn child, not just a viable one.

The federal government already has a similar law, named for Laci Peterson, the pregnant California woman whose husband Scott killed her in 2002. So do 38 other states.

But not Maryland, where the issue has been wrapped up in the politics of abortion. Abortion rights advocates are concerned that this is a slippery slope and that if you define fetuses as people the next step would be banning abortion.

"That to me seems an odd argument, that an unborn child with a name, that we're afraid of defining that as a person," said Maryland State Sen. Justin Ready (R-Judicial Proceedings Committee). The mother clearly felt, her feeling was that the unborn child was a person. She was going to care that child to term. she'd given him a name."

In fact, the bill specifically excludes abortion. It's says medical professionals cannot be held liable for administering lawful medical care.

A study at Johns Hopkins found 15 percent of the murders of women of reproductive age were of women who were pregnant or have just given birth.