Jessica Tinoco was a 34-year-old Simi Valley receptionist and mother of five who was stabbed to death by her live-in boyfriend, Ramon Joseph Rivas, on September 27, 2024, during a domestic dispute at their apartment on California Avenue. Two of her children were home when it happened, and her daughter called 911. In May 2026, Rivas pleaded guilty to second-degree murder and now faces up to 51 years to life in state prison.
What Happened That Night
Around 6:00 p.m. on September 27, 2024, Simi Valley police responded to a domestic violence call in the 800 block of California Avenue. Investigators say Rivas and Tinoco had been arguing when Rivas went into the kitchen, took a steak knife, and stabbed Tinoco in the face, abdomen, and arms. Four of the wounds were fatal.1KTLA. Simi Valley Man Guilty of Murder of Girlfriend
Two of Tinoco’s children were in the home. Her daughter placed the 911 call, telling the dispatcher that her mother was being stabbed by the boyfriend they lived with.2Ventura County Star. Raymond Ramon Rivas Pleads Guilty to Murder of Girlfriend in Simi Valley The children fled the apartment during the attack.3NBC Los Angeles. Simi Valley Mother of 5 Fatally Stabbed, Boyfriend Arrested
Officers arrived to find Rivas walking out of the home shirtless with blood on his upper torso. Tinoco was on the floor just inside the front door. A bent, blood-stained steak knife was recovered from the living room, and blood was found throughout the residence.4Ventura County District Attorney. Simi Valley Man Pleads Guilty to Murdering Girlfriend Rivas was arrested at the scene without incident. Tinoco was taken to Los Robles Regional Medical Center and pronounced dead.5Ventura County District Attorney. Boyfriend Charged With Murder in Simi Valley Domestic Violence Stabbing
Who Ramon Rivas Was
Rivas, born February 17, 1990, had prior convictions for carjacking and robbery and had previously served state prison time.6Simi Valley Acorn. Man Pleads Guilty in Fatal Stabbing of Mother of Five When he killed Tinoco he was on Post Release Community Supervision, a form of court-supervised release following a prison term.3NBC Los Angeles. Simi Valley Mother of 5 Fatally Stabbed, Boyfriend Arrested Prosecutors alleged the murder counted as a third strike under California’s Three Strikes Law. Rivas was not related to any of Tinoco’s children.7Simi Valley Acorn. Remembering Jessica
The Charges and Guilty Plea
The Ventura County District Attorney’s Office initially charged Rivas with murder under California Penal Code section 187(a), along with four counts of child endangerment and a special allegation for use of a deadly weapon. Senior Deputy District Attorney John Barrick of the Major Crimes Homicide Unit prosecuted the case.5Ventura County District Attorney. Boyfriend Charged With Murder in Simi Valley Domestic Violence Stabbing Rivas initially pleaded not guilty and was held without bail at the Todd Road Jail.
On May 20, 2026, at an early disposition conference, Rivas withdrew that plea and pleaded guilty to second-degree murder. He admitted every special allegation and aggravating factor charged: use of a deadly weapon, great violence and cruelty, a particularly vulnerable victim, danger to society based on his record, his strike priors, and a prior serious felony conviction.6Simi Valley Acorn. Man Pleads Guilty in Fatal Stabbing of Mother of Five The four child endangerment counts are to be dismissed at sentencing under the plea agreement.2Ventura County Star. Raymond Ramon Rivas Pleads Guilty to Murder of Girlfriend in Simi Valley
In a statement about the plea, prosecutor John Barrick said, “There is no amount of time the defendant could serve in prison that could ever balance the scales of justice against the horrors the children witnessed and the complete disregard for their wellbeing the defendant demonstrated.”8KEYT. Ramon Joseph Rivas Convicted for Stabbing and Killing His Then-Girlfriend in Front of Her Children
Sentence Rivas Faces
Rivas faces a maximum of 51 years to life in state prison. That figure combines the base sentence for second-degree murder with consecutive enhancements for the deadly weapon use, the prior serious felony conviction, and the Three Strikes designation. Sentencing is set for July 9, 2026, at 8:30 a.m. in Courtroom 26 of Ventura County Superior Court.4Ventura County District Attorney. Simi Valley Man Pleads Guilty to Murdering Girlfriend
Who Jessica Tinoco Was
Jessica Marie Tinoco was born on January 7, 1990, and grew up in Oxnard, California. She worked as a receptionist and was raising five children, ages 5 to 14 at the time of her death.7Simi Valley Acorn. Remembering Jessica
About 100 people gathered for a candlelight vigil at the Port Hueneme Pier on September 30, 2024, with friends and family wearing purple. A memorial service was held on October 19, 2024, at Conejo Mountain Memorial Park in Camarillo.9Camino del Sol Funeral Home. Jessica Tinoco Obituary All five children are now with relatives.
Amanda Salazar, a member of Tinoco’s extended family, organized a GoFundMe to cover counseling and immediate needs for the children. It had raised more than $23,000 from 341 donors toward a $100,000 goal.10GoFundMe. Join Us in Supporting Jessica’s Family