A former Yolo County Sheriff’s Office lieutenant is one of five people charged with murder following a fireworks warehouse explosion that killed seven workers in the rural Northern California community of Esparto last summer, authorities said.

Samuel Machado is accused of illegally having 1 million pounds of fireworks on his property at the time of the blast and using his law enforcement position to shield the illicit operation from scrutiny for years, according to the Yolo County district attorney’s office.

Machado was placed on administrative leave following the violent July 1 explosion, which was felt by residents up to 20 miles away, destroyed a family farm and sparked a 78-acre grass fire.

Devastating Pyrotechnics LLC and Blackstar Fireworks, Inc., are accused of manufacturing and storing explosives — including some too powerful to even be legally considered fireworks — on Machado’s property. On Friday, Yolo County Dist. Atty. Jeff Reisig announced a 30-count felony indictment had been filed against seven people connected to the blast, following the largest investigation he’s seen in two decades at the office. A separate five-count felony indictment was filed against an eighth defendant, Machado’s wife.

The most serious counts are seven second-degree murder charges — one for each of the warehouse workers who died.

An investigative report filed by a Yolo County civil grand jury last month stated that various top county authorities were aware of the sprawling illegal operation for at least three years prior to the lethal explosion, yet failed to take action.

A county Building Services Department official received a tip that the property was being used by two pyrotechnics businesses in June 2022, according to the report. Department officials wrote in emails that they would inspect the site, but noted they would “tread lightly” as the property was owned by “deputies that we work with.”

“Inexplicably, no code enforcement occurred, even though all dangerous fireworks had been banned by ordinance throughout rural Yolo County since 2001,” the report states. “In the absence of official oversight and enforcement, unmitigated expansion of the fireworks businesses operating at the site in Esparto led directly to death and destruction.”

In addition to Machado, the owner of Devastating Pyrotechnics, Kenneth Chee, operations manager Jack Lee and business partner Gary Chan Jr. all were charged with murder, as was Douglas Tollefsen of Blackstar Fireworks, Inc.

Machado’s wife, Tammy, was working at the Sheriff’s Office in an administrative position at the time of the blast. She also has been placed on leave and was charged in a separate indictment with child and animal endangerment for allegedly storing illegal fireworks at their property, as well as tax fraud and mortgage fraud.

The 30-count indictment alleges a decadelong conspiracy that “turned the property of a former Sheriff’s Lieutenant Sam Machado into the Northern California hub for an illegal enterprise that imports illegal explosives on the black market,” Yolo County Deputy Dist. Atty. Clara Nabity said at a Friday news conference.

Devastating Pyrotechnics is accused of expanding its footprint from 13 storage containers on Machado’s property in 2015 to more than 50 containers and a 5,000-square-foot warehouse in 2025.

During that period, the enterprise allegedly imported more than 11 million pounds of explosives and related materials onto a site located near residents and a family pool, Nabity said. None of the storage containers were licensed by the Bureau of Alcohol, Tobacco, Firearms and Explosives, and there are no licenses that permit the storage of explosives near homes and public roadways, Nabity said.

Other counts filed in the indictments include charges for having a dangerous workplace, unlawfully causing a fire, insurance fraud, child endangerment, animal cruelty, tax fraud and possession of illegal assault weapons.

Seven people charged in connection with the explosion were arrested in a sweeping operation early Thursday morning, Reisig said, including Blackstar Fireworks owner Craig Cutright. Ronald Botelho III, who worked for Blackstar, has been in custody since December on separate charges, the Associated Press reported, and on Thursday was charged for his alleged role in the explosion.

Chee, the owner of Devastating Pyrotechnics, was arrested in Orlando, Fla. Jail records obtained by Monterey Bay area news station KSBW indicate that he was apprehended at Disney World.

The defendants are scheduled to be arraigned Monday, Reisig said. Chee and another defendant who was arrested outside the county will be arraigned once they have been transferred to local custody, he added.

“This investigation has thus far involved dozens, maybe hundreds of law enforcement agencies around the state and the country,” Reisig said. “It has taken us across California, it’s taken us across the nation and it’s even taken us across our national borders.”

The seven workers killed in the explosion were identified as Christopher Goltiao Bocog, 45, and Neil Justin Li, 41, of San Francisco; Joel Jeremias Melendez, 28, of Sacramento; Carlos Javier Rodriguez-Mora, 43, of San Andreas; brothers Jesus Manaces Ramos, 18, and Jhony Ernesto Ramos, 22, of San Pablo; and Angel Mathew Voller, 18, of Stockton, according to the Yolo County coroner’s office.

The families of the victims filed a $35-million claim against the county and state fireworks regulators alleging widespread negligence for allowing the illegal operation to continue.