A longtime Yolo County sheriff’s deputy whose property was tied to a fireworks operation that exploded in Esparto, killing seven people and injuring two others, quietly retired two months after the July blast.

She never returned to work, according to officials.

Reiko Matsumura, who served nearly 18 years as a deputy, left the Yolo County Sheriff’s Office in September, a department spokesperson confirmed to The Sacramento Bee this month. Her departure came after the July 1 explosion that also destroyed a home on a compound where commercial fireworks had been stored and may have been illegally remanufactured.

The compound along County Roads 23 and 86A — owned by Matsumura’s sister, Tammy Machado, and her husband, Lt. Sam Machado — was next door. Matsumura’s similarly sized parcel on County Road 86A also housed fireworks in several containers licensed by the Bureau of Alcohol, Tobacco, Firearms and Explosives that were not part of the explosion, The Bee previously reported.

July’s deadly fireworks explosion started inside an improperly permitted warehouse operated by Devastating Pyrotechnics on the Machados’ compound. A Cal-OSHA investigation found that Devastating, owned by Bay Area resident Kenneth Chee and one of two pyrotechnics companies operating on the land, committed numerous safety violations on-site and lacked proper safety measures for its employees, many of whom were paid under the table. The agency fined Devastating Pyrotechnics $221,000.

The Machados, both employees of the Sheriff’s Office, were placed on administrative leave in the days following the inferno and have not returned to work, deputies said. Sheriff Tom Lopez also recused the Sheriff’s Office from the investigation.

All four parcels, each about 20 acres, are held under a revocable trust in the family’s name, according to property records.

Matsumura was not on leave

Matsumura’s connection to Esparto, the Machados and Lopez — as well as to local law enforcement and the firefighting and pyrotechnics communities interwoven in the July disaster and its aftermath — runs deep.

Matsumura is a fourth-generation resident of Esparto, nestled at the foot of the Capay Valley. Her father, Jerry, was a local fire commissioner and member of the Western Pyrotechnic Association. He died in 2015, according to previous Bee reporting.

Reiko Matsumura joined the Sheriff’s Office in 2002, according to the agency. She graduated from the Los Rios Corrections Academy in 2004 and the Yuba College Police Academy in 2006, before becoming a deputy in 2007. She held a variety of roles in her 23-year career, including as a records specialist, a detective, a correctional officer, a court bailiff and a transport deputy.

Lopez named Matsumura as resident deputy for the Capay Valley under a revived program aimed at assigning deputies to the communities where they live. Lopez, who was the fire chief of neighboring Madison Fire Protection District for a decade before his election to sheriff in 2018, told the Davis Enterprise in 2022 that he once coached Matsumura in Little League. Himself a fifth-generation Yolo County resident and resident of Esparto, Lopez also once served as a resident deputy there, according to his Sheriff’s Office biography.

Matsumura was selected as a Yolo County Public Safety hero of the year in February.

“Deputy Matsumura’s career is one of selfless dedication and service at the highest levels to our community and the law enforcement profession,” said Rep. Mike Thompson, D-St. Helena, who presented the award and later announced the recognition on the floor of the House. Over her 20-plus-year career, Thompson said, Matsumura demonstrated “exceptional leadership, professionalism and a steadfast dedication to public service.”

However, in the days following the explosion, she did not return to duty. The reasons for her absence was not disclosed though she was not placed on administrative leave, said Jennifer Davis of the professional standards unit at the Sheriff’s Office.

No charges directly tied to deadly blast

No one has been charged in connection with the explosion as Yolo County District Attorney’s Office investigators and Cal Fire’s Office of the State Marshal continue their investigation.

The probe, however, has stretched statewide.

In July, a week after the blast, law enforcement officials raided a San Francisco home connected to Devastating Pyrotechnics, the company tied to the blast. State fire officials gave little information at the time, saying only that investigators were “actively tracking down numerous leads and have served multiple search warrants as part of the investigation.”

Cal Fire and Yolo County district attorney’s investigators seized fireworks and other explosive materials from an East Los Angeles home in October. They recovered illegal fireworks and arrested the homeowner, Luis Acosta, on explosives and weapons-related charges.

Last week, on the other side of the state along the North Coast, authorities including Yolo DA investigators seized more fireworks from a home in Crescent City; one man was arrested in Del Norte County.

In both raids, authorities have publicly said the seizures were linked to the investigation into the Esparto blast but have not said how.

In May, two months before the deadly blast at the sprawling Esparto facility that housed Devastating Pyrotechnics and other companies, investigators in Commerce, Los Angeles County, seized pallet loads of fireworks belonging to Kenneth Chee, one of Devastating Pyrotechnics’ owners, a Sacramento Bee investigation revealed.

The Bee also learned in its investigation that a Cal Fire arson and bomb inspector had visited the Commerce site May 2, weeks before the May 21 seizure, and two months before the fateful explosion — a discovery that should have led inspectors to connect dots between the Commerce warehouse and fireworks factory in Yolo County, a pyrotechnics safety expert told The Bee.

Devastating Pyrotechnics has since been levied steep fines by state regulatory agency Cal-OSHA, the Division of Occupational Safety and Health, listing 15 serious violations totaling $221,000, in a citation issued Dec. 1.

The Machados remain on administrative leave, Sheriff’s Office spokesperson Lt. Don Harmon said. He said an internal investigation of the couple could not be completed by the agency until the criminal investigation ends.

The Bee’s Darrell Smith and Joe Rubin contributed to this story.