In response to a horrific crime March 18, during which a pregnant woman’s womb was cut open and her 34-week-old fetus destroyed, the president of Colorado’s state senate is promising to introduce legislation “to provide justice for both victims,” the woman and her fetus.

Pro-choice activists say such a law is unnecessary, and it could be used to restrict abortion rights and undermine the civil rights of pregnant women by subjecting them to bogus criminal investigations, arrests, and convictions based on the legal rights of the fetus.

Media coverage of the assault against Michelle Wilkins, which occurred in the Denver suburb of Longmont, was stoked by Rep. Gordon Klingenschmitt (R-Colorado Springs), a radical anti-choice legislator, who stated during a podcast prayer on March 25 that the brutal attack was a “curse of God upon America for our sin of not protecting innocent children in the womb.”

As the criminal investigation moves forward, Colorado Senate President Bill Cadman, a Republican, says the state needs a fetal-homicide law that will allow a fetus to be considered the victim of a crime.

“What about the baby?” Cadman said in radio interview March 30. “Why doesn’t a baby in Colorado, or an infant, or whatever you want to define—why don’t they receive the same protection in Colorado that they do in 38 other states?”

During the radio interview, Cadman, who has not released a draft of his bill, said his legislation would “provide a protection for a woman to do with her body as she desires,” indicating that he apparently intends to protect abortion rights.

Pro-choice advocates say Colorado laws already mandate severe punishments for crimes like the one committed against Wilkins, and even if Cadman’s new law explicitly protects a women’s right to have an abortion, it could still be twisted to punish women who have abortions.

It could also put the civil rights of pregnant women at risk, subjecting them to criminal charges of all sorts.

“There are commentators who look at feticide laws and argue that they can be narrowly tailored and limited to punishment of third parties,” said Lynn Paltrow, director of National Advocates for Pregnant Women. “And so they have argued there shouldn’t be any objection from pro-choice organizations and advocates for women. In theory, they are correct. But our research shows that in the current U.S. political environment, there is no way to put one of these laws in place without it becoming a tool for controlling and punishing pregnant women themselves.”

Paltrow, an attorney, said feticide laws have been used to charge women who suffered stillbirths or had newborns die in multiple states, including California, Georgia, Tennessee, South Carolina, and Utah. A woman who has an abortion can be charged by prosecutors who could define her abortion as something else, Paltrow said.

She pointed to two examples in which prosecutors ignored explicit language in feticide laws stating that women were not supposed to be arrested.

In one 1973 California case, a pregnant woman who shot herself in the abdomen was charged with murder, even though the murder statute, which covered the unlawful killing of a fetus, exempted “act[s] solicited, aided, abetted, or consented to by the mother of the fetus.” After a journey through the courts, the murder charge was replaced with the charge of illegal abortion.

And in Missouri, from 1999 to 2007, 22 women were charged with child endangerment after their newborns tested positive for cocaine.

Prosecutors relied on a state law that made all of Missouri’s laws, including its child endangerment and murder laws, applicable to “unborn children” from the moment of conception. Prosecutors simply disregarded the part of that same law that said nothing in this law’s section shall be interpreted as creating a cause of action against a woman for “failing to properly care for herself.”

These charges were dropped after years of court battles, but some of the women had already pleaded guilty to the charge or others.

Colorado lawmakers passed statutes in 2013 and 2014 that added severe criminal and civil penalties for committing crimes against pregnant women—over and above the punishments for crimes against the woman herself.

In fact, even though prosecutors are not able to file murder charges for the loss of the fetus, other charges against Dynel Lane, who allegedly attacked Wilkins in Colorado last month, could land her in jail for more than 100 years. Lane faces an attempted murder charge for her assault on Wilkins, as well as first degree felony charges under Colorado’s 2013 Crimes Against Pregnant Women Act.

Cadman remains adamant that Colorado requires legal protections for fetuses.

Paltrow counters that there’s no evidence that fetal homicide laws protect women.

“We need to acknowledge a collective horror at this attack and grief for this pregnant women and her loss,” Paltrow told Rewire. “But we need to focus on how to end violence against pregnant women, not how to use violence against women to advance opportunistic legislation that in the end is used to hurt pregnant women.”

Fetal homicide laws in 38 states vary widely. Some define life as beginning at early stages of development, while others specifically exclude abortion and prohibit considering pregnant women as perpetrators of fetal-homicide crimes.

It’s unclear how many of Cadman’s fellow Republicans, particularly “personhood” supporters who opposed Colorado’s existing crimes-against-pregnant-women law, will support the bill if it includes language allegedly protecting a woman’s right to abortion care.

State political observers said passage of Cadman’s bill through the Republican-controlled state senate is highly uncertain, and may depend on the votes of pro-choice Democrats.