“Risk To Public Safety” Pleads Not Guilty To Martinez Murder Charge

From the Office of the District Attorney

Martinez Resident Charged with Murder, Faces Special Circumstance Allegation

Martinez, California – The Contra Costa County District Attorney’s Office filed a felony complaint charging 36-year-old Marcos Eduardo Iriarte-Valdez of Martinez with the murder of Todd Stewart of Martinez, who was 68 years old at the time of his death.

On August 6, 2026, at approximately 5:10 pm, Iriarte-Valdez stabbed Todd Stewart to death with a knife while committing a residential burglary. The Martinez Police Department quickly identified and located Iriarte-Valdez with assistance from the public and through multiple investigative sources. This included video surveillance capturing events related to the crime, as well as physical evidence processed by the Contra Costa County Sheriff’s Office Crime Lab.

On August 11, 2026, the Martinez Police Department presented the case to the Contra Costa County District Attorney’s Office for review. That same day, the District Attorney’s Office filed a criminal complaint charging Iriarte-Valdez with one count of murder for the unlawful killing of Todd Stewart.

The complaint also includes three additional enhancements to the murder charge:
• Killing during a burglary: The District Attorney’s Office alleges the murder took place while the defendant was committing, attempting, or fleeing a burglary. This special allegation, if found true by a jury, means the defendant could face life in prison without the possibility of parole.
• Use of a knife: The complaint alleges that Iriarte-Valdez personally used a knife during the commission of the crime, which qualifies as a serious felony enhancement under state law.
• Committed while out on conditional release: At the time of the killing, Iriarte-Valdez was out of custody on electronic monitoring, as ordered by the court, in a separate, unrelated burglary case.

Contra Costa County District Attorney Diana Becton said, “Our office will pursue this case with diligence and integrity to hold Iriarte-Valdez fully accountable under the law for this devastating act of violence. Our thoughts are with the victim’s loved ones and the larger community as they navigate this unimaginable loss. Our Victim-Witness Assistance Program is available to guide the family members through the criminal justice process and connect them with the services and support they may need.”

Iriarte-Valdez was arraigned today in Contra Costa Superior Court, pleading not guilty to the murder charge and denying all enhancements. Judge David Goldstein, who presided over the arraignment, called the defendant “a risk to public safety” and ordered him held without bail. The case returns to court September 1st at 8:30 am before Judge Michael Nieto in Richmond to set a preliminary hearing date.