A man accused of being a central figure behind last year’s deadly fireworks explosion in Esparto made his first brief court appearance Thursday after being returned to Yolo County.
Kenneth Chee, the owner of Devastating Pyrotechnics, was dressed in striped jail clothing as he stood before Judge Stephen Mock. He did not enter a plea, and Chee’s defense attorneys asked that his arraignment be moved to June 1 to join other defendants in the case. He was remanded into custody without bail.
A representative from the California Attorney General’s Office — Deputy AG Kevin Bell — appeared on behalf of the California Board of Optometry. He recommended that if bail is granted in the future for Chee, he would not be allowed to take any action where a license is required. Media reports previously indicated Chee had worked as an optician for Costco.
Chee’s defense attorneys also requested prosecutors not search his seized phones and electronic devices without a third party or “special master” present due to the potential presence of privileged attorney-client information. A similar request had been made the day before by other defense teams.
Chee and seven other defendants were indicted almost two weeks ago in connection with the July 1, 2025 explosion. He faces 28 charges including seven counts of second-degree murder — one for each Devastating Pyrotechnics employee killed in the blast. Four other defendants face the same murder charges.
Chee is also accused of importing illegal explosives designed and packaged for consumer sale, branded under the label “Bean Day Ho.”
Chee was arrested at Disney World in Florida on April 9 on a fugitive from justice charge, and briefly appeared in Orange County court the following day. He was extradited back to California and booked into the Monroe Detention Center in Woodland on Wednesday.
Who is Kenneth Chee?
According to business records filed with the California Secretary of State’s office, Kenneth Chee established Devastating Pyrotechnics in 2013. He was authorized to operate out of Esparto in 2015 by the property owner, former Yolo County Sheriff’s Lieutenant Samuel Machado, who also faces seven counts of second-degree murder.
According to a report released by a Yolo County civil grand jury last month, Chee was also a former business partner of Machado’s late father-in-law Jerry Matsumura. The latter was a former fire commissioner with the Esparto Fire Protection District, and known for putting on local fireworks displays.
The Yolo County District Attorney’s Office said Devastating Pyrotechnics’ operation in Esparto grew substantially over the following decade, from 13 storage containers to more than 50, in addition to a 5,000 square-foot warehouse.
Aerial photographs taken February 2022, November 2023 and June 2024 of the Esparto property where the fireworks facility was located. The construction of the new building is seen in the lower right of each image, along with added storage containers.Google EarthChee held a state pyrotechnic license issued by Cal Fire’s Office of the State Fire Marshal, which revoked the licenses last August after determining Chee had violated state fireworks laws and regulations.
Chee also applied for a federal fireworks license, but was denied by the federal Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) due to a prior criminal conviction in the 1990s. Federal regulations prohibit people convicted of a crime punishable by a year or more in prison from receiving or possessing explosive materials, or being issued a federal explosives license or permit. Chee reportedly applied to the ATF for “relief from disabilities” in 2009 but was rejected.
Prosecutors have described the Esparto operation as a “criminal enterprise” and part of a “decade-long conspiracy” that imported more than 11 million pounds of black-market fireworks over that time.
Chee was identified as being a leader being allegedly supported by co-conspirators including his half-brother Gary Chan, who held federal explosives licenses, and uncle Jack Lee, Devastating Pyrotechnics’ operations manager. Both also face multiple felony counts, including murder.
Before its website was taken down, Devastating Pyrotechnics advertised it had more than three decades of experience designing and producing fireworks shows. The company focused heavily on display fireworks for big productions and supplied pyrotechnics for shows in Northern California.
A joint statement released by Marysville, Yuba City, Sutter and Yuba counties on July 2 called Devastating Pyrotechnics a “trusted partner and a cherished part of our regional fireworks celebrations.” City and county officials said some of the fireworks intended for the region’s July 4 show had been destroyed in the blast.
The DA’s office said in its indictment that roughly a million pounds of pyrotechnics and explosives were stored on the property on July 1 when the explosion occurred. A defense attorney said last week the cause was an “industrial accident” when workers were inserting electronic igniters or fuses into fireworks.
Prosecutors said the initial blast happened where Devastating Pyrotechnics stored its explosives, instantly killing seven workers.
Property damage is shown at the location of a July 1, 2025, fireworks explosion in Esparto, Calif., Friday, April 10, 2026.AP Photo/Jeff ChiuCalifornia workplace safety officials issued 15 citations to Devastating Pyrotechnics and its successors in December in connection to the tragedy, totaling $221,000 in fines.
An alleged illicit history
An April 13 bail motion filed by the district attorney’s office shed more light on the extent of Chee’s alleged illegal activities, before and after the Esparto tragedy.
Prosecutors described the company owner as being “indifferent” to the dangers of the “illegal, overcharged explosives” he was buying and selling.
The DA’s office said Devastating Pyrotechnics’ products were connected to at least three incidents before the Esparto explosion, including one additional death.
Prosecutors said an 18-year-old man, identified by media as Marciano Antone-Gordon, was “decapitated” by one of Chee’s devices branded “Northern Beast” during a 2024 New Year’s celebration in the Bay Area. Chee allegedly kept importing and selling Northern Beast despite Antone-Gordon’s death.
Devastating Pyrotechnics was also reportedly linked to a June 2023 explosion at a three-story building in San Jose, and a May 2025 raid of a warehouse in Commerce that seized more than 100,000 pounds of illegal fireworks.
Prosecutors wrote even after the Esparto explosion Chee remained focused on rebuilding his illegal operation, including searching for property in Nevada with other co-conspirators.
Chee also reportedly remained in contact with individuals in the Bay Area, elsewhere in California, China and Malaysia who are involved in the illegal explosives business, and tried to “recruit new workers to join his enterprise.”
The DA’s office also accused Chee of showing “brazen disdain for victims and the law” by attempting to participate in San Francisco’s 2026 Chinese New Year celebration and attending its pyrotechnics display, despite having no valid license.
