A sweeping criminal investigation into last summer’s deadly Esparto fireworks explosion culminated Thursday in multiple arrests, including a sheriff’s lieutenant, his wife and the Bay Area owner of the fireworks company long suspected of being at the center of the blast.
At least four of those arrested were charged with seven counts of murder — one for each victim — along with a litany of other felony charges, including conspiracy and the illegal handling and possession of fireworks.
Yolo County prosecutors did not name the suspects Thursday, but online jail and court records showed at least six people connected to the July 1 fireworks explosion were arrested during the day in California and Florida. A seventh suspect, who was arrested last year, had additional charges related to the explosion added Thursday.
They include Sam Machado, a Yolo County Sheriff’s Office lieutenant, and his wife Tammy Machado, who owned the property where fireworks were warehoused, were both taken into custody Thursday. Tammy Machado, who is on paid administrative leave from her job as a Sheriff’s Office employee, was bonded out shortly after booking. Sam Machado, also on leave, remains in custody, jail records show.
Sam Machado was among at least three individuals who will be charged with seven murder charges in connection to the blast — one for each victim who died.
Kenneth Chee, the founder and CEO of Devastating Pyrotechnics, was also arrested. Despite being ineligible for a federal explosives permit, Chee ran Devastating Pyrotechnics, a display and wholesale fireworks company that marketed itself to municipal clients as a lower-cost option and imported tens of thousands of pounds of fireworks annually. Devastating was the larger of the two companies that stored fireworks in Esparto.
Chee was arrested Thursday while vacationing at a Disney resort with family near Lake Buena Vista, Florida, outside of Orlando.
Jack Y. Lee, operations manager for Devastating Pyrotechnics, was arrested and booked into Yolo County custody on Thursday. Lee is listed as the registered owner of the San Francisco home Devastating Pyrotechnics used as its business address.
Lee was expected to be charged with 16 felony counts, including seven counts of murder. Bail was denied, jail records show.
Gary Y. Chan Jr., who obtained the federal explosives permit for Devastating Pyrotechnics, was arrested and booked into jail Thursday in Santa Clara County. Chee was ineligible to obtain the permit due to prior criminal convictions.
Chan was expected to be charged with multiple felony counts including murder. He is ineligible for bail.
Also arrested was Craig Cutright, a longtime show producer for Devastating Pyrotechnics who formed his own fireworks company, BlackStar Fireworks, in 2023. Cutright served as a volunteer firefighter for the Esparto Fire Protection District for about two years before the explosion. Cutright faced 12 felony charges, including illegal possession of explosives, manufacturing destructive devices and conspiracy to commit a crime. He remained in custody with bail set at $500,000, according to jail records.
Ronald Botelho III was arrested in December in Crescent City. Botelho sold fireworks for Cutright. On Thursday, additional charges were added, according to the Del Norte Sheriff’s Office, including felony reckless possession of explosives, conspiracy to commit a crime and making destructive devices without permits.
The Yolo County District Attorney’s Office said it would hold a news conference Friday morning to announce the indictments.
The grand jury was impaneled by the Yolo County District Attorney’s Office, which led a nine-month criminal investigation that District Attorney Jeff Reisig described as the most complex in county history.
The investigation revealed a sprawling fireworks operation spanning nearly the length of California, based on property owned by the Machados and operating with the tacit permission of local building and fire officials. Sam Machado also operated a gun dealership, Sam’s Gun Sales, on the Esparto compound.
Prosecutors under Yolo County District Attorney Jeff Reisig worked closely with the Office of the State Fire Marshal, the division of the California Department of Forestry and Fire Protection that regulates fireworks. Cal Fire focused on the cause of the explosion and completed its investigation in February.
The investigation led to the October discovery of illegal fireworks in the east Los Angeles home of Luis Acosta, which prompted a nearby high school’s evacuation. In December, investigators seized a cache of illegal fireworks in Crescent City and arrested Botelho.
The investigation also prompted greater scrutiny of other fireworks-related incidents, including a 2023 explosion in San Jose and a record-setting seizure in the Los Angeles County city of Commerce just weeks before the Esparto blast.
The warehouse leased by the fireworks company lacked critical safety features, a Cal-OSHA investigation found. It also lacked required local permits, a civil grand jury found last month.
Nineteen claims were filed against Yolo County after the explosion. In December, a $35 million claim was filed by family members of the victims and nearby residents. Those claims were denied, leaving claimants until late July to file lawsuits.
Online jail records showed Sam Machado remained in custody at the Sutter County Jail as of 2 p.m. Cutright was booked in Yolo County around 10 a.m. and remained in custody at the Monroe Detention Center in Woodland as of late Thursday afternoon. Chee remained in custody in Central Florida.
The Bee’s Madison Smalstig, Michael McGough and Daniel Hunt contributed to this story.
This story was originally published April 9, 2026 at 5:33 PM.
Related Stories from Sacramento Bee
The Sacramento Bee
Daniel Lempres is an investigative reporter at The Sacramento Bee focused on government accountability. Before joining The Bee, his investigations appeared in outlets like the San Francisco Chronicle, the Los Angeles Times and The New York Times.
The Sacramento Bee
Joe Rubin, an Emmy award-winning investigative reporter for The Sacramento Bee, unpacks complex systems with an eye toward holding power to account. Rubin’s reporting for the San Francisco Chronicle, NPR and Capital & Main has led to state laws protecting workers from lead poisoning and has exposed wasteful spending.