Ventura County District Attorney Erik Nasarenko announced that Gerardo Arroyo Almanza, of Simi Valley, has pled guilty to second-degree murder for the killing of his father, Alfredo Arroyo Sancen. Almanza also pled guilty to three counts of criminal threats against additional family members. He admitted to a prior strike offense and a special allegation for the use of a weapon.
On April 6, 2024, several of Almanza’s family members drove to his residence in Simi Valley to check on his well-being. While they were near their vehicles parked across the street, Almanza ran out of the house, confronted his family members with a knife and threatened to kill them. Almanza chased his mother and father around a parked car. After catching his father and pinning him to the ground, Almanza stabbed him several times.
As neighbors began to gather, Almanza ran from the area. An EMT-trained neighbor provided first aid to Sancen before he was transported by emergency medical services to the hospital. Sancen died at Los Robles Regional Medical Center. Simi Valley Police Department officers quickly arrived on scene and arrested Almanza, who was hiding a block away from the crime scene.
On March 6, 2025, the court-appointed mental health expert determined that Almanza was incompetent to stand trial. On October 6, 2025, Almanza was deemed competent for trial.
Senior Deputy District Attorney Theresa Pollara, a member of the Ventura County District Attorney’s Office Major Crimes Unit, prosecuted the case.
“This guilty plea brings accountability for Gerardo Almanza’s brutal act of violence against his father and his threats of violence against other family members,” Ms. Pollara said. “Our hope for the family is that they are able to move forward in their healing.”
Almanza is scheduled to be sentenced on September 11, 2026, at 9:00 a.m. in courtroom 12 of the Ventura County Superior Court. He remains in custody without bail. Almanza is facing 30 years to life plus an additional term of nine years and four months in state prison.