A former firefighter arrested nearly three years ago on suspicion of detonating an improvised explosive device and planting several others across El Dorado and Sacramento counties was convicted of all the criminal charges he faced.

Benjamin Edward Cunha, 44, of Orangevale, on Friday pleaded no contest to all 41 felony charges he faced, the El Dorado County District Attorney’s Office announced Monday in a news release.

Prosecutors said Cunha’s no contest plea was not the result of a plea deal, and it will be up to El Dorado Superior Court Judge Thomas Smith to determine the appropriate sentence. Cunha faces a maximum sentence of more than 80 years in prison.

“The conduct Mr. Cunha admitted to put people throughout our region at risk,” District Attorney Vern Pierson said in the news release. “I hope he spends a very long time in prison and serves the full sentence the court imposes, without being released early.”

In January 2024, El Dorado County sheriff’s officials said Cunha was arrested following an investigation into a “series of improvised explosive devices that had been placed alongside roads and highways, in multiple locations in El Dorado County and Sacramento County.” The California Highway Patrol said at the time that Cunha was apprehended after an “intense operation” in which an explosive ordinance disposal team carried out “critical search warrants.”

The former firefighter was convicted in federal court long before the improvised explosive investigation.

Cunha was convicted of arson in 2016 after pleading guilty to setting at least 30 fires in rural areas east of Sacramento during 2006 and 2007, causing $7 million in damage, The Sacramento Bee reported at the time. He was sentenced in early 2017 to five years in prison and agreed to pay $246,862 in restitution to Cal Fire.

He set the fires after serving as a volunteer firefighter for the Diamond Springs Fire Protection District in El Dorado County. Cunha also worked from 2001 to 2003 as a seasonal firefighter for Cal Fire, The Bee reported.

Cunha “was motivated by boredom and the desire to be paid overtime when called out to fight fires,” according to a written plea agreement filed in U.S. District Court in Sacramento in the arson case. Even though he was a volunteer, he could have been eligible for payment during busy periods, Robert Combs, chief of the Diamond Springs district, said at the time.

The charges in the explosives case stem from incidents from December 2022 through January 2024. Prosecutors said there were 18 incidents in El Dorado County and 23 in Sacramento County.

Cunha was convicted of 15 counts of use of a destructive device and explosive to injure or destroy; eight counts of possessing a destructive device in a place where people are present: seven in or near a public place and one at a home; 10 counts of possessing a destructive device without a California Department of Justice permit and four counts of possessing ingredients to make a destructive device.

He also was convicted of three counts of possessing a firearm by a convicted felon and one count of child endangerment under circumstances likely to produce great bodily harm or death.

The investigation that led to Cunha’s prosecution was done by the Sheriff’s Office, the CHP, the Sacramento County Sheriff’s Office and the FBI.

El Dorado County Sheriff Jeff Leikauf said in the news release that investigators dedicated countless hours to ensure Cunha will be held accountable for his actions “that could easily have cost innocent people their lives.”

On Monday, Cunha remained in custody at the El Dorado County Jail. He’s scheduled to return to court Jan. 29 for his sentencing hearing. Prosecutors said they will be seeking the maximum sentence for Cunha.

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