In a Simi Valley killing that stunned neighbors and family alike, Ramon Joseph Rivas, 36, has pleaded guilty to second-degree murder in the fatal stabbing of his girlfriend, Jessica Marie Tinoco, Ventura County prosecutors said. The attack unfolded on Sept. 27, 2024, inside the apartment the couple shared, and prosecutors say several of Tinoco’s children saw the violence firsthand. Rivas admitted special allegations, including using a deadly weapon and that the crime involved great violence, and he remains jailed without bail as he waits to be sentenced.
Plea and court timeline
Court records show Rivas entered the guilty plea during an early disposition conference on May 20. As reported by the Ventura County Star, he admitted 10 special allegations and agreed that four child-endangerment counts will be dismissed at sentencing, which is scheduled for July 9. The Ventura County Superior Court docket reflects the plea entry in the case file.
Prosecutor's statement
Senior Deputy District Attorney John Barrick, identified by the DA as a member of its Major Crimes Homicide Unit, said in a statement posted by the Ventura County District Attorney’s Office that “this murder was a tragedy, but what made it so incomprehensible was the fact that the defendant murdered Jessica in front of her children.” The DA's Facebook post served as the office's public notice of the plea and outlined the admitted allegations. Ventura County District Attorney
The killing and local reaction
The attack was reported shortly before 6 p.m. on Sept. 27, 2024, when officers responded to a domestic-violence call and found Tinoco suffering from multiple stab wounds. She later died at Los Robles Regional Medical Center, according to the Los Angeles Times. Two of Tinoco’s children were among those who witnessed the stabbing and called 911, and local coverage chronicled the community’s grief, including vigils and community reaction in the weeks that followed.
What comes next legally
When Rivas was charged in October 2024, the Ventura County District Attorney’s Office listed counts including PC 187(a) murder and several special allegations, such as alleged use of a knife as a deadly weapon and prior strike convictions. The official news release lays out the charges and the case number. The DA's October 2024 news release identifies the defendant as Ramon Joseph Rivas (DOB 02/17/1990) and lists the alleged enhancements. Sentencing is scheduled for July 9, and court records and reporting indicate the child-endangerment counts will be dismissed under the plea agreement.
