In California, Miguel Angel Espino’s 2018 Riverside County case became part of the stakes in a Monterey County murder verdict.
DESERT HOT SPRINGS, Calif. — Years before a Monterey County jury convicted Miguel Angel Espino of killing an inmate, prosecutors said he nearly killed his father and left him inside a burning mobile home.
The earlier case began Aug. 7, 2018, in a mobile home park on Palm Drive in Desert Hot Springs. It ended with Espino entering state prison in February 2024 for attempted murder, aggravated mayhem and arson. Six months after that, authorities said, Espino attacked Michael R. Spengler at Salinas Valley State Prison. On April 23, 2026, a jury found Espino guilty of first-degree murder in Spengler’s death.
The Riverside County facts became important again because they shaped Espino’s potential punishment in Monterey County. The court found true that Espino had three prior 2024 convictions from Riverside County that qualify as strikes under California law. Prosecutors said those convictions were attempted murder, mayhem and arson. After the new murder verdict, the Monterey County District Attorney’s Office said Espino faces 75 years to life in prison, to be served after the seven-years-to-life sentence he already had.
Riverside County prosecutors said Espino and his father, Arturo Espino Sr., had argued often before the 2018 attack. Court filings described regular disputes and physical altercations, many tied to the younger Espino’s outbursts. In one earlier incident, neighbors allegedly saw Miguel Espino pin his father’s arms behind his back and drag him across a roadway in the mobile home park. Other outbursts included vandalism at the father’s home. By the afternoon of Aug. 7, 2018, prosecutors said, the conflict had narrowed to father and son inside the residence.
What happened next formed the core of the attempted murder case. Prosecutors said Espino used a hammer and a rock to beat his father about the head, causing major trauma. After Arturo Espino dropped unconscious to the floor, prosecutors said, Miguel Espino gathered clothes, used flammable liquids and set the pile on fire in the hallway. He then ran from the home. The fire did not spread into a larger disaster because neighbors saw smoke and went inside. They used an extinguisher, called 911 and pulled Arturo Espino outside.
Fire crews arrived moments later and knocked down the smoldering blaze. An arson investigator determined that the fire was intentional. Arturo Espino was taken to Desert Regional Medical Center in Palm Springs. Doctors were initially unsure whether he would survive because of the injuries, according to court filings. He remained in a coma for days before waking up. Prosecutors later used the beating, the fire and the father’s injuries to support charges of attempted murder, arson, aggravated mayhem and weapon-related sentencing allegations.
Investigators identified Miguel Espino as the prime suspect after speaking with neighbors and his mother. Court records said Espino’s mother had moved out of the mobile home park and obtained a restraining order against him because she feared for her life and property. Espino was found Aug. 8, 2018, and arrested without incident. He denied harming his father. Prosecutors said monitored jail calls with his mother contradicted that denial. In one call, he said his father tried to assault him with a knife and that he struck his father with a rock and hammer.
Espino also told investigators another person had been inside the home and started the fire, according to filings. At the time the Riverside County case moved to trial in 2023, prosecutors said Espino had no documented prior felony convictions in the county, though he had several unresolved misdemeanor cases. The trial began at the Banning Justice Center before Riverside County Superior Court Judge Francisco Navarro. Espino was later convicted and received a life term with the possibility of parole, entering state custody on Feb. 8, 2024.
His time in state prison soon led to a new homicide case. The California Department of Corrections and Rehabilitation said Espino was at Salinas Valley State Prison in Soledad on Aug. 19, 2024, when he attacked Spengler at 10:31 a.m. Prison staff stopped the assault, called for medical aid and contacted 911. Paramedics pronounced Spengler dead at 11:08 a.m. Officers recovered an inmate-made weapon at the scene. State officials said no staff members or other incarcerated people were injured. Espino was placed in restricted housing as the investigation began.
Monterey County prosecutors later said Spengler was stabbed 42 times on the prison recreation yard and died from injuries that caused extensive bleeding. District Attorney Jeannine M. Pacioni announced that Espino had been convicted of willful, deliberate and premeditated murder. Superior Court Judge Stephanie E. Hulsey presided over the trial. Jurors also found that the killing involved a high degree of cruelty, viciousness and callousness. The prison’s Investigative Services Unit and Monterey County District Attorney Investigator Dominique Hohmann investigated the case.
Spengler was serving one of California’s harshest sentences when he was killed. He had been received from Los Angeles County on Aug. 9, 2022, to serve life without parole for first-degree murder and second-degree murder. His convictions involved the winter 2013 killings of Michael Meza, 32, of Pomona, and Marcus Nieto, 26, of Azusa. At sentencing, Los Angeles County Superior Court Judge Henry J. Hall said the murders appeared to be surprise ambushes of Spengler’s friends. Hall said he believed Spengler should never be released.
The Monterey County case also turned on the state’s repeat-offender law. Espino’s prior convictions from the Riverside County attack on his father were not background facts alone. They were strike offenses that increased the consequences of the prison murder conviction. Prosecutors said the 75-years-to-life term would be consecutive to Espino’s existing seven-years-to-life sentence. That means the new sentence would begin after the old one, creating a layered punishment for crimes committed in two counties and in two very different settings.
Salinas Valley State Prison, where Spengler died, opened in 1996 and houses more than 3,300 incarcerated people in minimum-, medium-, maximum- and high-security custody. It employs about 1,500 people and offers academic and vocational programs. The attack drew state and local review, including notice to the Office of the Inspector General and a coroner’s determination process. Prosecutors have not publicly announced Espino’s sentencing date in the murder case.
The Monterey County case now returns to court for punishment, closing the trial phase of a record that moved from a Desert Hot Springs mobile home to a state prison yard in Soledad.
Author note: Last updated May 21, 2026.