Those charged with murder can no longer cite infidelity as provocation to kill, Supreme Judicial Court rules

John Adams Courthouse, home to the Massachusetts Supreme Judicial Court and the Massachusetts Appeals Court.Lane Turner/Globe Staff/File

The state’s high court shed centuries of misogynistic reasoning Monday, declaring a man can no longer avoid a murder conviction by saying he killed a woman because she told him she had been unfaithful.

The unanimous ruling by the Supreme Judicial Court left in place two first-degree murder convictions for Peter Ronchi, who in 2009 killed his girlfriend Yuliya Galperina, who was nine months pregnant, after she told him the child she was carrying was not his.

At trial, Ronchi testified he was so enraged by Galperina’s statement that he “lost it” and stabbed her 15 times and left her to bleed to death in her Salem apartment.

Writing for the court, Justice Frank M. Gaziano said the brutal attack against Galperina, 42, and her unborn child warranted life without parole sentences and that Ronchi’s request that his conviction be reduced to manslaughter because Galperina’s words provoked him into killing her was no longer legally valid.

“We conclude that the exception in the Commonwealth to the mere words rule for sudden oral revelations of infidelity has run its course. The exception rests upon a shaky, misogynistic foundation and has no place in our modern jurisprudence,” Gaziano wrote. “Going forward, we no longer will recognize that an oral discovery of infidelity satisfies the objective element of something that would provoke a reasonable person to kill his or her spouse.”

Ronchi’s appellate lawyer, reached by phone Tuesday, had no immediate comment on the ruling.

Essex District Attorney Paul F. Tucker praised the court’s decision.

“I’m pleased the Supreme Judicial Court affirmed the defendant’s convictions in the brutal slayings of Yuliya Galperina and her unborn son,” Tucker said. “The SJC has fully recognized that this defense has no place in a modern society.”

In a concurring opinion, Justice Elspeth B. Cypher said recent studies have shown a horrifying level of violence against pregnant women in the United States. A 2022 study found women are more likely to be killed during pregnancy or shortly after giving birth than die from three major causes of maternal deaths.

“The brutal facts of this case are not an anomaly. The disconcerting frequency of lethal violence against pregnant women warrants concomitant response from our justice system,’' she wrote. “This court’s acknowledgement that oral revelations, on their own, cannot induce a reasonable person to kill their pregnant partner is a laudable first step. I would take it one step further and reject the principle that discovery of infidelity, whether oral or through personal observation, can amount to adequate provocation to kill a partner, standing alone.”

Ronchi was, in fact, the father of Galperina’s unborn child, the court said.

The court ruled it was explicitly disavowing the concept, most recently spelled out in a 1981 decision known as Commonwealth v. Schnopps, that women were in any way responsible for their own murders.

The SJC also focused on a second legal issue raised by Ronchi. He claimed he could not be convicted of first-degree murder for the death of the unborn child because none of his stabbing blows struck its body, an idea the court flatly rejected.

Ronchi “committed an act of violence against a woman who was nine months pregnant, repeatedly stabbing her in, among other areas, the torso, where the vital organs are located,” Gaziano wrote. “By ending the mother’s life, he destroyed the viable fetus through the cessation of life-sustaining maternal blood flow.”

And in a clearly symbolic action, the SJC agreed with the trial judge that Ronchi deserved two life sentences without the possibility of parole for his crimes.

“The defendant contends that this sentencing scheme violated the prohibition against double jeopardy,” Gaziano wrote. “The judge had authority to impose consecutive sentences for the unlawful killings of a mother and her viable fetus.”

Ronchi is currently serving his sentences at MCI-Norfolk, a medium security prison, according to the Department of Correction.

Travis Andersen of the Globe Staff contributed to this report.