RIVERSIDE, Calif. — A San Jacinto woman who fatally stabbed her live-in boyfriend on the Fourth of July in 2021 was sentenced Friday to 16 years to life in state prison, closing a case that a Riverside County jury decided with a second-degree murder conviction this summer.
Wynette Clara Nunez, 43, was sentenced by Riverside County Superior Court Judge Charles Koosed at the Riverside Hall of Justice, according to MyNewsLA. Nunez was convicted in August of the 2021 slaying of Mauro Villasenor, 27, her live-in boyfriend of roughly nine months.
TL;DR: Wynette Clara Nunez, 43, of San Jacinto, was sentenced Oct. 23, 2026, to 16 years to life in prison for the July 4, 2021, stabbing death of her boyfriend, Mauro Villasenor, 27. A Riverside jury convicted her in August of second-degree murder plus a deadly-weapon enhancement. Prosecutors said she grabbed kitchen knives during a rage over his involvement with an ex-girlfriend.
A Fourth of July That Turned Deadly
According to a trial brief filed by the Riverside County District Attorney’s Office, Nunez and Villasenor had lived together for roughly nine months before the fatal night. “By all accounts, the defendant and Villasenor did not fight with each other and were in a loving relationship,” the brief stated.
But sometime during the first half of 2021, Villasenor began secretly seeing his ex-girlfriend, identified in court documents only as “O.O.” The encounters eventually became known to Nunez and her family, prosecutors said. Whether she ever argued with Villasenor about the relationship was never established at trial.
On the evening of July 4, 2021, Nunez, Villasenor, and one of her sisters held a small Fourth of July celebration at his home in the 100 block of Boxelder Way, near Elderberry Street in San Jacinto. They drank cognac and appeared to be in good spirits, according to court papers.
The 30 Minutes That Changed Everything
Nunez’s sister left shortly before 10 p.m. What happened in the following half-hour was never fully reconstructed by sheriff’s investigators, but at some point prosecutors said Nunez went into the kitchen and grabbed more than one knife.
She then stabbed Villasenor below the right collarbone, above the left eyebrow, and slashed his left forearm, according to the prosecution’s brief.
Just after 10 p.m., Nunez called 911, shouting, “Please send someone; he’s going to die!” She told the dispatcher, “I don’t know what happened,” gave her address, and hung up.
When deputies arrived minutes later, they found the front door bolted and could not get in despite repeated knocking. They tried kicking the door, then used a battering ram to force entry, court papers stated. Inside, they discovered Nunez on the floor with Villasenor, who was unconscious, as she cried. Several kitchen knives were found on the countertop and dining room table — one with apparent blood on it — and blood smears were found around the kitchen sink and the upstairs bathroom sink. Paramedics pronounced Villasenor dead at the scene.
A Story That Didn’t Add Up
Central Homicide Unit detectives detained Nunez for questioning. She initially said she had left the house and returned to find Villasenor dying on the floor. But security camera footage around the property failed to corroborate her story, and she later admitted she had never left the house that night, according to the prosecution.
Detectives also asked whether she wanted to write a letter to her late boyfriend. She agreed, allegedly writing: “I’m sorry. There’s nothing I can say to justify what I’ve done … I hate myself for what happened. I can’t even wrap my head around it. I never meant for it to happen.”
The Verdict and the Sentence
After deliberating less than a day, a Riverside jury found Nunez guilty of second-degree murder in August 2026. Jurors also found true a sentence-enhancing allegation that she personally used a deadly weapon — a knife — in the commission of the felony.
At Friday’s sentencing hearing, Judge Koosed imposed the sentence required under state law for second-degree murder with a deadly weapon: 16 years to life in state prison.
FAQ
Who is Wynette Clara Nunez?
Wynette Clara Nunez, 43, is a San Jacinto, California, woman convicted of second-degree murder for the July 4, 2021, stabbing death of her live-in boyfriend. She was sentenced Oct. 23, 2026, to 16 years to life in prison.
Who was the victim?
Mauro Villasenor, 27, also of San Jacinto. He and Nunez had lived together for roughly nine months and were described in court papers as being in a loving relationship.
What happened on the night of July 4, 2021?
After a small Fourth of July celebration with Nunez’s sister at Villasenor’s home, Nunez grabbed kitchen knives and stabbed Villasenor below the right collarbone, above the left eyebrow, and slashed his forearm. She called 911 just after 10 p.m., and paramedics pronounced him dead at the scene.
What triggered the attack?
According to the prosecution’s trial brief, Villasenor had secretly been seeing his ex-girlfriend during the first half of 2021, and the encounters became known to Nunez and her family. Whether the two argued about it was never established.
What did the jury decide?
In August 2026, after less than a day of deliberations, a Riverside jury convicted Nunez of second-degree murder and found true the allegation that she used a deadly weapon.
What sentence did she receive?
16 years to life in state prison, imposed Oct. 23, 2026, by Judge Charles Koosed at the Riverside Hall of Justice — the sentence required under California law for the conviction.
Did Nunez change her story?
Yes. She initially told detectives she had left the house and returned to find Villasenor dying, but security camera footage did not support that account, and she later admitted she had never left the house that night.
Where was Nunez held before sentencing?
She was held without bail at the Smith Correctional Facility in Riverside County following her conviction.
Featured image: Riverside County Sheriff SUV. Photo via Law Commentary.
