Colorado voters will cast ballots next year on a measure that would redefine the definitions of “person” and “child” in the state’s constitution to include unborn fetuses after proponents turned in more than enough signatures to qualify for the ballot.

The measure, which will be dubbed Amendment 67, is backed by Personhood Colorado, a pro-life organization that has been behind several other attempts to give fetuses legal standing.

The group turned in more than 140,000 signatures, well over  the 86,105 signatures needed to get on the ballot. Colorado Secretary of State Scott Gessler’s office said Monday that a sufficient number of signatures were valid, giving the amendment a spot on the ballot next year.

“This will be the first time that an amendment of this nature will be on the ballot in Colorado. This is a very different take on a sort of personhood amendment,” said Jennifer Mason, a spokeswoman for Personhood Colorado.

The group’s previous efforts to define a fetus as a child failed in 2008 and 2010, and didn’t get enough signatures to make the ballot in 2012. But Mason said in an interview Tuesday that Amendment 67 is different: The measure would change the Colorado Criminal Code and the Colorado Wrongful Death Act to allow prosecutors to file charges against anyone who commits violence against a fetus; earlier proposals would have simply changed the Colorado constitution’s definition of a person to include fetuses.

Still, abortion rights advocates cast the law as old news that Colorado voters had already rejected.

“This is the third time we’ve seen a personhood ballot measure, and we don’t know what they don’t understand about the word ‘no,’ ” said Karen Middleton, executive director of NARAL’s Colorado branch.

“Each time, there’s an effort to reframe the debate or suggest the debate is somehow different,” Middleton said. “It may be in a different package, but it’s the same basic attempt to ban abortion even in cases of rape and incest.”

The proposed amendment stems from a July 2012 traffic accident, in which a serial drunk driver crashed into a car carrying Heather Surovik. The crash killed Surovik’s unborn child, Brady, but the drunk driver wasn’t charged in his death. Personhood Colorado has dubbed their new effort the Brady Amendment.

“The Brady Amendment requires Colorado to recognize that there are two victims in cases like mine,” Heather Surovik said in a statement. Surovik had lobbied the legislature for a bill that would allow prosecutors to press charges in cases that included the death of a fetus, but the bill the legislature eventually passed only angered abortion opponents even more.

“They just packed it full of things to protect Colorado abortion clinics,” Mason, of Personhood Colorado, said.