In 1680, English nobleman Edward Coke codified his country's common law regarding fetal homicide.

"[T]his is a great misdemeanour, and no murder," Coke wrote of the intentional death of a fetus in utero "by Potion, Battery, or other cause."

If a man strike a woman so that she lose her child, he shall pay ten shekels for her loss. - The Code of Hammurabi, Babylon, circa 1754 BCE

Three-hundred years later, America adhered to its own “born alive” equivalent. It wasn't until a ruling in a 1984 Massachusetts court case, Commonwealth v. Cass, that a U.S. state began expressly protecting fetuses from assault or murder, according to a 2014 article in the Indiana Law Journal.

Pennsylvania enacted a variation in 1997 to punish the intentional, non-abortion deaths of gestating children.

Today, the commonwealth is one of 40 states to pass state laws or uphold judicial cases that provide fetal homicide protection.

Some require viability outside the womb; others define victimhood only in the latter stages of pregnancy. Twenty-six states deem the non-abortion death of a fetus homicide at any stage of development.

If men strive, and hurt a woman with child, so that her fruit depart from her, and yet no mischief follow: he shall be surely punished, according as the woman's husband will lay upon him; and he shall pay as the judges determine. And if any mischief follow, then thou shalt give life for life. - The King James Bible, Book of Exodus, 21:22-23, circa 600 BCE

Pennsylvania's law is in this last category, and could be invoked in the fatal Wilkinsburg shootings of March 9. Duquesne youth Eric Taylor was also recently convicted of the criminal homicide of an unborn child.

In the 10 states that don’t have fetal homicide laws, including Pennsylvania’s neighbors Delaware and New Jersey, the murder of a pregnant woman carries no greater charge than the killing of any other person.

But the tendency has been toward greater and greater protections for fetuses throughout human history.

Two states – Colorado and Maine – have laws that can impose harsher punishments for the murder of pregnant women as opposed to non-pregnant victims, but don’t provide specific protections for the fetuses themselves.

Farah Diaz-Tello, senior staff attorney with the National Advocates for Pregnant Women, said the distinction is important. She said laws like Colorado’s 2013 “Crimes Against Pregnant Women Act” may be less common than what she calls “fetal victim laws,” but she thinks they’re more in line with existing legal standards regarding fetuses in the U.S.

If a woman be quick with child, and by a Potion or otherwise killeth it in her womb; or if a man beat her, whereby the child dieth in her body, and she is delivered of a dead child, this is a great misdemeanour, and no murder: but if the child be born alive, and dieth by the Potion, Battery, or other cause, this is murder. - Edward Coke, The Third Part of the Institutes of the Laws of England, 1680 CE

“What that law does is acknowledges the special loss that is experienced by the pregnant woman, rather than saying that fetuses are victims that should have their own set of rights, which is unprecedented in terms of our jurisprudence,” Diaz-Tello said.

According to a study by the Maryland state government, murder was the leading cause of death in pregnant women through the 1990s, with one of every five deaths caused by homicide. Among non-pregnant women, only about 6 percent of deaths were attributed to murder.

Diaz-Tello said it’s hard to say whether fetal victim laws are actually preventing murders of pregnant women.

“Fetal victim laws are passed in the name of protecting women from harm. We know that during pregnancy, women are particularly susceptible to intimate partner violence. But there is really no data that supports the idea that these have been effective in deterring violence against pregnant women,” Diaz-Tello said.

Court records show at least six men and women have been charged with fetal homicide in Western Pennsylvania since 2002. The law will likely be cited again if charges are brought in the fatal shooting of Chanetta Powell.

But state fetal homicide laws aren't always so clear cut. Diaz-Tello said even those with express exemptions for the mothers of the fetuses have been used as grounds to prosecute women who’ve lost unborn children for various reasons.

“So that could be using a controlled substance, refusing caesarian surgery (or) being involved in a car accident not wearing a seatbelt,” Diaz-Tello said.