Seven people — including a sheriff’s lieutenant — have been arrested in connection with an explosion at an illegal fireworks facility in rural Yolo County that killed seven last July.

The massive series of explosions at the farm near Esparto leveled buildings and storage structures and ignited a 78-acre fire in an agricultural area about 40 miles northwest of Sacramento.

On Friday, Yolo County District Attorney’s Office officials announced murder charges for five people, along with conspiracy charges for those five plus two others allegedly involved in an illegal fireworks storage and wholesale operations known as Devastating Pyrotechnics, Devastating Pyro Displays and BlackStar Fireworks.

The businesses used property on a farm owned by Yolo County Sheriff’s Office Lt. Samuel Machado and his wife Tammy, who also worked for the Sheriff’s Office.

Facing seven counts of murder are Samuel Machado, Kenneth Kin Chee, Gary Chan Jr., Jack Lee and Douglas Michael Tollefsen.

They are also facing charges of conspiracy to possess explosive devices, possession of explosives and transportation of explosives, among other things, along with Craig Allen Cutright and Ronald John Botelho III, according to an indictment filed on April 3 in Yolo County Superior Court.

FILE: Smoke rises from the scene of a massive fire at a warehouse storing fireworks in rural Yolo County on Tuesday, July 1, 2025. The bodies of seven people were recovered from the rubble. (Cal Fire LNU via Bay City News)

Property owners face separate charges

In a separate filing, Tammy Machado is facing charges of mortgage fraud, filing false tax returns, animal cruelty and child endangerment.

Samuel Machado is also facing charges of child endangerment, animal cruelty, tax fraud and illegal possession of assault weapons.

The cover of a March 26, 2026, Yolo County Civil Grand Jury report that found illegal fireworks activity had been operating for years at the Machado property in Esparto with the full knowledge of nearly a dozen county employees and political leaders. (Yolo County)

Last month, a scathing civil grand jury report found that the illegal fireworks business had been operating for years at the Machado property with the full knowledge of nearly a dozen county employees and political leaders, who fostered an atmosphere of permissiveness with regards to how the county oversees farmers and their land.

“Although numerous local officials, including Sheriff’s deputies, fire officials, officials in the County building, code enforcement, planning and County Counsel’s office, all knew about the fireworks businesses, none of them took any action,” according to the report.

The report goes on to say it’s possible that the county looked the other way, in part, because it was reluctant “to antagonize some sheriff’s officials by initiating an enforcement action on property owned by sheriff’s department employees.”

It also found that while the Yolo County Board of Supervisors paid lip service to the need for reforms, there is currently no evidence that it has initiated any sort of thorough or systematic review of county processes or procedures.

The victims who died in the explosion were identified as Neil Justin Li, 41, of San Francisco; Christopher Goltiao Bocog, 45, of San Francisco; Jesus Manaces Ramos, 18, of San Pablo; Jhony Ernesto Ramos, 22, of San Pablo; Angel Mathew Voller, 18, of Stockton; Carlos Javier Rodriguez-Mora, 43, of San Andreas; and Joel Jeremias Melendez, 28, of Sacramento.

Kiley Russell writes primarily for Local News Matters on issues related to equity and the environment. A Bay Area native, he has lived most of his life in Oakland. He studied journalism at San Francisco State University, worked for the Associated Press and the former Contra Costa Times, among other outlets. He has covered everything from state legislatures, local governments, federal and state courts, crime, growth and development, political campaigns of various stripes, wildfires and the aftermath of Hurricane Katrina.