A Monterey County jury found Miguel Angel Espino guilty after a fatal 2024 attack inside Salinas Valley State Prison.
SALINAS, Calif. — A California prisoner already serving seven years to life now faces 75 years to life after a jury convicted him of murdering another incarcerated man, prosecutors said.
The conviction against Miguel Angel Espino, 33, links two criminal proceedings in two parts of California. The first came from Riverside County, where he was convicted in a violent attack on his father and a fire set inside a Desert Hot Springs mobile home. The second came from Monterey County, where prosecutors said Espino stabbed Michael R. Spengler 42 times on a recreation yard at Salinas Valley State Prison.
The Monterey County District Attorney’s Office said Espino was convicted April 23, 2026, of willful, deliberate and premeditated murder. District Attorney Jeannine M. Pacioni announced the verdict April 27. Superior Court Judge Stephanie E. Hulsey presided over the trial. Jurors also found true an allegation that the killing involved a high degree of cruelty, viciousness and callousness. The court separately found that Espino’s three Riverside County convictions from 2024 qualify as strike offenses under California’s Three Strikes Law.
Those findings are why prosecutors said Espino faces 75 years to life, consecutive to the sentence he was already serving. A consecutive term is served after another sentence, not at the same time. Espino’s existing term was seven years to life. It came from convictions for 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. State prison records show he was received from Riverside County on Feb. 8, 2024.
The prison killing occurred just over six months later. Corrections officials said Espino attacked Spengler at 10:31 a.m. on Aug. 19, 2024. Staff stopped the incident, called for medical assistance and contacted 911. Paramedics pronounced Spengler dead at 11:08 a.m. Officers recovered one inmate-made weapon. State officials said no staff members or additional incarcerated people were injured. Espino was moved to restricted housing while Salinas Valley State Prison’s Investigative Services Unit and the Monterey County District Attorney’s Office investigated.
Prosecutors said prison medical staff tried to save Spengler, but he died at the scene from injuries that caused extensive hemorrhaging. The Office of the Inspector General was notified, and the Monterey County Coroner was assigned to determine the official cause of death. District Attorney Investigator Dominique Hohmann also worked on the case. Prosecutors did not announce a public motive in the verdict release. The records made public so far describe the weapon, the location, the number of wounds and the emergency response, but not why the attack happened.
Spengler, 38, was also serving a life sentence. State prison officials said he was received from Los Angeles County on Aug. 9, 2022, to serve life without the possibility of parole for first-degree murder and second-degree murder. His convictions came from the killings of Michael Meza, 32, of Pomona, and Marcus Nieto, 26, of Azusa, during the winter of 2013. At sentencing, Los Angeles County Superior Court Judge Henry J. Hall said both killings appeared to be surprise ambushes of friends. Hall said he believed Spengler was extremely dangerous and should never be released.
The older Riverside County case against Espino involved different victims, different investigators and a different setting. Prosecutors said Espino and his father, Arturo Espino Sr., had a troubled history before the 2018 assault. Court papers described frequent arguments and some physical fights. They also described earlier outbursts that included vandalism at the father’s mobile home. In one alleged incident, neighbors saw Miguel Espino pin his father’s arms behind his back and drag him across a roadway in the mobile home park where his parents had lived.
On Aug. 7, 2018, prosecutors said, father and son were alone inside the mobile home in the 15600 block of Palm Drive in Desert Hot Springs when another confrontation turned violent. Miguel Espino beat Arturo Espino with a hammer and a rock, causing major head trauma, prosecutors said. After his father fell unconscious, Espino gathered clothing, used flammable liquids and set the pile on fire in the hallway, according to court filings. He then ran from the home, leaving the injured man inside as smoke began to draw attention from neighbors.
The neighbors’ response changed the outcome of that case. They entered the burning home, used an extinguisher to contain the fire, called 911 and pulled Arturo Espino outside. County fire personnel arrived moments later and put out the remaining fire. An arson investigator determined the blaze was intentional. Arturo Espino was taken to Desert Regional Medical Center in Palm Springs. Doctors were initially unsure whether he would survive the beating. He remained comatose for days, then regained consciousness. An update on his later condition was not included in the public case summaries.
Desert Hot Springs police and Cal Fire arson investigators focused on Miguel Espino after speaking with neighbors and his mother. Court filings said his 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 arrested Aug. 8, 2018. Prosecutors said he denied harming his father, but recorded jail calls with his mother confirmed his role. In one call, he said his father tried to attack him with a knife and that he struck him with a rock and hammer.
Espino also told investigators someone else had been inside the home and started the fire, according to court filings. The Riverside County case went to trial in 2023 at the Banning Justice Center after several days of jury selection. Prosecutors called witnesses and presented the family history, the fire evidence, the medical injuries and the recorded calls. At that time, Espino had no documented prior felony convictions in Riverside County. The convictions that followed later became strike offenses when the Monterey County court considered the punishment range in the prison homicide.
Salinas Valley State Prison opened in 1996 and houses more than 3,300 people in several security levels, from minimum to high security. The prison employs about 1,500 people and offers academic classes and vocational programs. The homicide case shows how a violent incident inside a state prison can move through several layers of review: prison staff response, medical aid, restricted housing, investigative services, district attorney review, jury trial and sentencing. The verdict resolved the question of guilt, but not the final sentence.
Espino remains in custody while the Monterey County case awaits sentencing. Prosecutors said the expected term is 75 years to life, served after his current seven-years-to-life sentence, making the next hearing the point where the new punishment becomes part of the official prison record.
Author note: Last updated May 21, 2026.