A 36-year-old Venezuelan migrant, identified as Marcos Iriarte-Valdez, is accused of fatally stabbing 68-year-old Todd Stewart outside Stewart's Martinez, California home last week. The Department of Homeland Security confirmed Iriarte-Valdez is an undocumented immigrant who allegedly committed the crime in a sanctuary state.
Iriarte-Valdez had been released from jail the day prior to the stabbing. He was in pretrial release for a residential burglary case and had been jailed the previous Tuesday for allegedly violating terms of his home-detention monitoring. A Contra Costa County Superior Court judge released him on his own recognizance and referred him back to home detention. Less than 24 hours later, Stewart was dead.
According to Martinez Police Chief Andrew White, the suspect's home-detention monitoring equipment was not placed on him until the day after the fatal stabbing. Iriarte-Valdez was arrested Friday evening at his home and is being held on $1.1 million bail. He faces charges of murder and committing a felony while released on his own recognizance.
Investigators used surveillance footage, automated license-plate recognition technology, and community tips to identify and locate the suspect. Police stated there was no known connection between Iriarte-Valdez and Stewart. Neighbors described Stewart as a retiree who was working in his garage before the attack.
Iriarte-Valdez's criminal record includes an arrest in October 2025 for driving under the influence of alcohol and hit-and-run causing property damage, according to county booking records and police statements. The Department of Homeland Security stated that Iriarte-Valdez should be transferred to their custody for removal from the country.