“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 9th at 8:30 am before Judge Michael Nieto in Richmond to set a preliminary hearing date.
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Even though he has a burglary track record, I didn’t think he was there to commit another burglary. Why kill when he could’ve easily driven away.
One possible scenario: He’s cruising the neighborhood/cul de sac in search of an opportunity, sees the open garage door at Mr. Stewart’s home, enters, and is confronted by Mr. Stewart.
Granted, we don’t have full access to surveillance cams or evidence so all to be taken with a grain of salt. He did make off with a laptop from a garage during one of the prior Orinda cases.
He’s been here illegally since 2007, and has a criminal history of burglary, DUI, hit and run, domestic violence, etc. I thought it was an odd way to dress to commit burglary, especially on a warm day. I believe he was confronted by Mr. Stewart, but stabbing is usually very personal. His electronic monitoring didn’t take effect until the day after the murder. Unbelievable.
Given that he supposedly worked for Boeing (a defense contractor!) I’m skeptical that his status has been illegal this whole time.
His criminal history also includes rape. I don’t think the media makes up criminal charges or how long someone has been in the country illegally. They “FACT CHECK.” This was a reputable newspaper back east.
Why doesn’t any news agency publish the name of the judge who let him out on an OR / promise to appear on the burglary cases? We are asked to vote on these judges periodically – how we vote pro or con on a juge without this info?
Did the DA’s Office oppose him being released on the OR? Did they speak in court against it? How can we vote for against a DA without this info?
The East Bay Times / Mercury article (“Once an engineer with a bright future, Martinez murder suspect’s life collapsed over 18 months”, by Nate Gartrell) goes into depth about this:
“Over the next three months, two different Contra Costa judges signed off on his release, likely due to a recent California Supreme Court ruling that has changed how bail is set statewide. Issued April 30, the so-called Kowalczyk decision requires defendants to be released or “affordable” bail to be set unless prosecutors can show “clear and convincing” evidence the defendant is likely to seriously hurt someone or skip out on court. Proponents of the decision say it’s in line with constitutional mandates, while police and prosecutors have largely decried it as a public safety threat.
Judge Jesse Hsieh initially released him back in May, but placed him on a home detention requirement. He was accused of violating the court’s order and brought before Judge Nichelle Holmes, a former Contra Costa prosecutor, who released Iriarte-Valdez on Aug. 5. The very next day, he allegedly showed up to Francis Court in Martinez and again attempted a daytime home burglary, resulting in the confrontation and Stewart’s violent death, according to prosecutors.”
Newsom appointed Contra Costa county judge
Nichelle Holmes.
Above is per California Post
There should be a way that the public can sue these judges for their continual mistake of letting violent criminals go only to repeat crimes. I feel sorry for the poor victims. They should be able to sue.
I’m also curious if the state of California gave this guy a driver’s license to cloak him in legallity.
A not dumb guy with underlying issues. We’re left to wonder how much he’s gotten away with prior to this tragic confrontation.
Judge Nishelle Holmes has a history of advocating for restorative justice. She goes out of her way to not lock people up. The California Post covered her career in a story. Please read. This is what we are up against.
I suspect there are at least a few qualified, conservative local lawyers who would be glad to be appointed to the bench and have their rulings informed by a public safety viewpoint, rather than sympathy with repeat wrongdoers, which is what seems to be in fashion. But unless California finds a way to elect a Republican governor, that will never happen. And in fairness, as noted elsewhere, as long as the supermajority Democratic Party legislature continues to put criminal-friendly laws on the books, even law-and-order judges find their hands tied.