Of course, the impulse to punish violence against pregnant women differently is widely shared and understandable. In the case of the Colorado stabbing, the victim, Michelle Wilkins, suffered an injury that was entirely entwined with her pregnancy, an injury not specified in the statutes covering assault and attempted murder that already carry lengthy prison sentences.

Granting fetuses victim status, however, does not address the core harm. When violence is done to a pregnant woman, her reproductive freedom is trampled.

A woman who is assaulted while pregnant reasonably fears the consequences for a pregnancy that she has chosen to carry to term. Abuse during pregnancy can cause miscarriage and stillbirth, as well as maternal substance use, delayed entry into prenatal care and low birth weight. The victim’s interest in her developing fetus is thus violated.

The law should provide a remedy. Reform matters because abuse of pregnant women is so common. The Centers for Disease Control and Prevention estimate that more than 300,000 pregnant women a year are victims of domestic violence. Unlike headline-grabbing cases like the Colorado attack, violence against pregnant women is usually inflicted not by strangers, but by current or former partners.

Yet the criminal law largely fails to account for how the fact of pregnancy defines the harm experienced by these women. Instead, Congress and most states have passed feticide laws. (A few states simply apply tougher penalties for existing offenses if the death or injury of a pregnant victim is involved.)

Only a few jurisdictions criminalize acts that cause a pregnant woman to lose her pregnancy. In 2013, Colorado enacted a crime of “unlawful termination of pregnancy” that expressly recognizes the pregnant woman as the victim of violence. Other states should follow suit and reject the wrongheaded logic of maternal-fetal conflict behind the new Colorado proposal.

That would be a start, but not sufficient. Cases of violence against pregnant women that don’t involve loss of pregnancy still lie largely beyond the reach of the law. A separate crime of assault on a pregnant woman would establish that a woman has a stake in her pregnancy, an interest worth protecting.