SLO County murder suspect was charged with 14 crimes over the last decade
The man accused of murdering his father and attempting to murder his mother has a long criminal history, which included two court orders for mental health treatment, court records show.
Alan Fonseca Osio, 29, was arrested Monday evening after he allegedly stabbed his father to death , assaulted his mother and set their house on fire, before attempting to flee the scene in the 200 block of Spruce Street.
Multiple neighbors told The Tribune that the victims, who lived inside the home, were Osio's parents, but police have not yet identified them.
Court records show Osio was arrested and charged with crimes 14 times since 2014. It is unclear at this time how many times he may have been arrested and not charged.
Nextdoor neighbor Damian Tejada told The Tribune that Osio broke into his home in 2023, but that he and his family didn't press charges after Osio's father apologized and explained his son had a mental health illness.
Neighbors described Osio's parents as kind people.
Murder suspect found incompetent to stand trial twice, records show
According to court records, Osio's earliest arrest was in 2014, when he was charged with failing to contact the owner of a vehicle after a hit-and-run, a misdemeanor. He pleaded no contest to that charge and was later charged with misdemeanor assault and corporal injury to a cohabitant or spouse. He pleaded no contest to the assault charge, and the corporal injury charge was dismissed.
In 2015 Osio pleaded no contest to disturbing the peace, and then in 2016 he pleaded no contest to a battery charge and disobeying a court order — both misdemeanors.
After that, Osio began a sequence of crimes in which his competency to stand trial in four cases was called into question over four consecutive years — 2017, 2018, 2019 and 2020.
In April 2017, Osio was charged with a misdemeanor DUI relating to a February 2017 incident. He pleaded no contest to the crime the day he was arraigned and waived his right to a lawyer, records show. He was put on probation without jail time on Feb. 28, 2018.
In addition to the DUI charge in 2017, Osio also pleaded no contest to misdemeanor possession of a controlled substance and misdemeanor resisting a peace officer or EMT In August 2017.
On Sept. 20, 2018, Osio was arrested on suspicion of felony attempted carjacking, assault with a deadly weapon, attempted kidnapping and attempted unlawful taking of a vehicle — about seven months after he was put on probation for the 2017 DUI offense.
In the carjacking case, Osio ultimately pleaded no contest to the assault with a deadly weapon charge on Feb. 5, 2019, and the other charges were dismissed, records show.
While he was awaiting sentencing, however, Osio was charged with a second DUI and attempted unlawful taking of a vehicle in a June 2019 incident, which also amounted to a probation violation for his previous cases. He pleaded no contest to the attempted unlawful taking of a vehicle charge and the DUI charge was dismissed.
He applied for mental health diversion for the violation but was denied on Aug. 5, 2019. He was ordered to receive mental health treatment from a state hospital the following month on Sept. 16, 2019. Records show he was ultimately admitted to the jail's competency treatment program rather than sent to a state hospital.
The treatment program applied to the probation violation. Records show the court ordered Osio to take anti-psychotic medication in order to regain his competency to stand trial in that case. Two months later, on Nov. 4, 2019, he was found competent to stand trial and returned to jail custody.
In March 2020, records show Osio was sentenced to two years in County Jail for the assault with a deadly weapon charge and 18 months in state prison for the attempted unlawful taking of a vehicle charge.
Then, while Osio was serving time in jail, he was charged with felony vandalism, felony assault with a deadly weapon and two counts of misdemeanor obstructing or resisting a police officer in relation to an incident on April 25, 2020.
He pleaded no contest to the vandalism charge. The other charges were dismissed "in the furtherance of justice," which means the judge found that Osio was unjustly charged for the crimes. He was sentenced to one year in state prison.
To dismiss a charge in the furtherance of justice, a judge must consider the defendant's background and constitutional rights, the circumstances of the case and other factors.
While he was serving his jail sentence, Osio was again ordered on June 29, 2021, to receive mental health treatment in a state hospital. Instead, he was admitted to the jail's competency treatment for the second time, records show. His treatment included psychotropic medication, records show, and he was found competent to stand trial on Dec. 14, 2021.
He was sent to serve his prison sentence in January 2022 and was released on parole April.
Osio was out on parole after serving time for the 2020 charge, records show, when he was caught shoplifting in July 2022 and charged with a misdemeanor. He pleaded no contest to that charge.
His most recent case before this week occurred in 2023, when he was cited for pubic intoxication, records show, but that charge was dismissed.
Suspect expected to appear in court on Thursday
On Wednesday evening, the San Luis Obispo County District Attorney's Office charged Osio with murder, attempted murder, arson and injuring a police animal.
The agency added sentencing enhancements to the murder charge for the use of a deadly weapon — a knife — and at least two previous serious felonies and to the attempted murder charge for inflicting great bodily injury and the use of a deadly weapon.
Osio was being held in San Luis Obispo County Jail custody without bail as of Wednesday.
He was scheduled to be arraigned Thursday morning in San Luis Obispo Superior Court.
