A horrifying knife attack against a pregnant woman and her teenage son on the Big Island in June has prompted a state lawmaker to draft new legal protections for expectant mothers that sidestep the divisive question of when human life begins.

State Rep. Tommy Waters, D-51st (Lanikai, Waimanalo), wants someone who attacks a pregnant woman to face the tougher prison sentences now applied to felony crimes committed against the elderly, children and people with disabilities.

Waters said his idea would protect pregnant women without giving any new legal recognition to the fetus that could infringe on abortion rights. Previous bills to protect unborn children have failed in the state Legislature because of the potential complication to abortion rights.

"I'm trying to figure out a way to protect the mother and the fetus without getting into the abortion debate," said Waters, the chairman of the House Judiciary Committee. "And I think we've come up with a solution."

Other key lawmakers and advocates who work with victims of domestic violence said they may support Waters next session. But the state public defender questions whether a new law is necessary because judges already have the power to impose longer sentences when there are aggravating circumstances, such as when a victim is pregnant.

In June, Tyrone Vesperas, a staff sergeant in the Hawai'i National Guard who had served in Iraq, was arrested by Big Island police after allegedly stabbing his estranged wife multiple times. Her unborn child did not survive, and the couple's 14-year-old son also was stabbed to death.

Waters, an attorney, said he drafted his proposal after reading about the Vesperas case in the newspaper. "I thought, 'Why aren't we protecting the status of pregnant women?' " he said.

Under his proposal, people would face mandatory minimum prison sentences without possibility of parole for felony crimes against pregnant women if they knew or reasonably should have known the woman was pregnant. Those who attack pregnant women would also be subject to extended sentences under a section of the law that now covers crimes against the elderly, children and the disabled, hate crimes, and crimes by repeat or dangerous offenders.

State Sen. Brian Taniguchi, D-10th (Manoa, McCully), the chairman of the Senate Judiciary and Labor Committee, said he anticipates several bills because of the Vesperas case and others that have been in the news over the past few years. But he said he is interested in Waters' idea.

"It seems to address what some of the concerns have been," he said.

Carol Lee, the executive director of Hawai'i State Coalition Against Domestic Violence, said new protections for pregnant women would be valuable but that the coalition would not support any bill that treats the mother and the fetus separately.

"We would probably favor increased penalties," Lee said. "Another thing we would like about this is that the focus is staying on the woman because the attack is on the woman primarily and may not cause injury to the fetus."

State Sen. Sam Slom, R-8th (Kahala, Hawai'i Kai), has sought legal protection for unborn children for the past several years and described Waters' approach as haphazard.

"It's an end-around so they don't have to deal with the fetus," he said. Slom had been influenced by the state Supreme Court's 2005 reversal of a manslaughter conviction against Tayshea Aiwohi, a Kane'ohe woman who caused the death of her newborn baby by smoking crystal methamphetamine, or ice, while pregnant. The court found that the fetus was not a person covered under state law when the woman used the drug.

At least 36 states have fetal homicide laws, according to the National Conference of State Legislatures, with at least 15 states with laws that apply to the earliest stages of pregnancy.

State Rep. John Mizuno, D-30th (Kamehameha Heights, Kalihi Valley, Fort Shafter), said he plans to introduce two bills next session to protect pregnant women and said he is discussing his plans with prosecutors.

His first bill would make it a second-degree felony to injure pregnant women with the intent to kill the fetus, a third-degree felony to injure pregnant women with reckless disregard for human life, and a misdemeanor to injure pregnant women through negligence. His second bill is similar to Waters' idea to add pregnant women to protected classes that trigger extended prison sentences.

"We avoid the whole choice issue," Mizuno said of abortion rights. Others in the House and Senate who have heard his proposal, however, believe it could be problematic because of its inclusion of the fetus.

Jack Tonaki, the state's public defender, said the increased penalties being discussed are not necessary. He said imposing mandatory minimum sentences, as Waters suggests, takes discretion away from judges to base sentences on the facts of each case. He also said that attacks on pregnant women are uncommon and, when they do occur, judges typically take the pregnancy of the victim into consideration when sentencing.

"I don't think there are many judges that will take an attack on a visibly pregnant woman lightly," Tonaki said.

Reach Derrick DePledge at ddepledge@honoluluadvertiser.com.