Miguel Angel Espino faces 75 years to life after jurors found he murdered another inmate with a prison-made weapon.

SALINAS, Calif. — A Monterey County jury has convicted a California prisoner of first-degree murder in the fatal stabbing of another inmate on a Salinas Valley State Prison recreation yard, prosecutors said.

Miguel Angel Espino, 33, was found guilty April 23, 2026, in the death of Michael R. Spengler, a 38-year-old prisoner who was serving life without parole for two Los Angeles County murders. The verdict adds a new case to Espino’s criminal record less than three months after he arrived in state prison for an earlier Riverside County case involving his father, a hammer, a rock and a fire set inside a mobile home.

The Monterey County District Attorney’s Office said Espino attacked Spengler on Aug. 19, 2024, at Salinas Valley State Prison in Soledad. Prosecutors said Espino used an inmate-made weapon and stabbed Spengler 42 times while the two men were on a recreation yard. The district attorney’s office said prison medical staff tried lifesaving measures, but Spengler died at the scene from injuries that caused extensive bleeding. District Attorney Jeannine M. Pacioni announced the conviction, and Superior Court Judge Stephanie E. Hulsey presided over the trial.

The jury found Espino guilty of willful, deliberate and premeditated murder. Jurors also found true an allegation that the killing involved a high degree of cruelty, viciousness and callousness, prosecutors said. The finding matters because Espino already had three prior convictions from Riverside County in 2024 that qualify as strikes under California’s Three Strikes Law. The court found those prior convictions true. Prosecutors said Espino now faces 75 years to life in prison, to be served after the seven-years-to-life term he was already serving.

State prison officials first described the case as a homicide investigation on the day Spengler died. The California Department of Corrections and Rehabilitation said the attack began at 10:31 a.m. Staff quickly stopped the incident, called for medical aid and contacted 911. Paramedics pronounced Spengler dead at 11:08 a.m. No prison staff members or other incarcerated people were injured, state officials said. Officers recovered one inmate-made weapon at the scene. Espino was placed in restricted housing while prison investigators and prosecutors reviewed the killing.

Espino had been received into state custody from Riverside County on Feb. 8, 2024. State records listed his commitment offenses as attempted first-degree murder, inflicting great bodily injury, personal use of a dangerous or deadly weapon, aggravated mayhem and arson of an inhabited structure with felony arson special circumstances. Those crimes came from an Aug. 7, 2018, attack on his father, Arturo Espino Sr., inside a mobile home in Desert Hot Springs. Prosecutors said father and son had argued often before the assault and that some prior disputes turned physical.

In the Riverside County case, prosecutors said Espino beat his father with a hammer and a rock during a confrontation at the home in the 15600 block of Palm Drive. Court filings described the father as unconscious after the beating. Prosecutors said Espino then gathered clothes, used flammable liquid and set a hallway fire before running from the home. Neighbors saw smoke, entered the burning residence, used a fire extinguisher and pulled Arturo Espino outside. Fire crews arrived soon after and put out the remaining fire. An arson investigator determined the fire had been set intentionally.

Arturo Espino was taken to Desert Regional Medical Center in Palm Springs. Doctors were first unsure whether he would survive because of the severity of the beating, according to earlier court filings. He remained in a coma for days before regaining consciousness. Investigators identified Miguel Espino as the prime suspect after speaking with neighbors and Espino’s mother, who had moved out of the mobile home park and had obtained a restraining order against her son because she feared for her life and property. Espino was arrested Aug. 8, 2018, without incident.

Espino denied hurting his father, but prosecutors said recorded jail calls with his mother tied him to the attack. In one conversation described in court records, Espino said his father tried to assault him with a knife and that he struck his father with a rock and a hammer. He also told investigators another person had been inside the home and had started the fire, court filings said. At the time of the Riverside County trial, prosecutors said he had no documented prior felony convictions in that county, though he had unresolved misdemeanor cases.

Spengler also entered state prison after a murder case. He was 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 killings of Michael Meza, 32, of Pomona, and Marcus Nieto, 26, of Azusa, during the winter of 2013. At Spengler’s 2022 sentencing, Los Angeles County Superior Court Judge Henry J. Hall said both murders appeared to be surprise ambushes of friends. Hall said he believed Spengler should never be released from prison and called him extremely dangerous.

The killing happened inside a large state prison that opened in 1996 and houses more than 3,300 people in minimum-, medium-, maximum- and high-security custody. The prison also employs about 1,500 people and offers academic and vocational programs. The attack was investigated by the prison’s Investigative Services Unit and Monterey County District Attorney Investigator Dominique Hohmann. The Office of the Inspector General was notified after the attack, and the Monterey County Coroner was assigned to determine Spengler’s official cause of death.

The verdict leaves sentencing as the next major step. Prosecutors said the new term would be served after Espino’s current life sentence, extending a case that began with a prison yard attack on Aug. 19, 2024.

Author note: Last updated May 21, 2026.