A former U.S. Navy SEAL has been convicted in connection with a thwarted plan to use explosives against law enforcement officers during a “No Kings” protest in California, after a concerned store clerk alerted authorities.
Gregory Vandenberg, 49, was found guilty following a five-day federal trial on charges of transporting explosives with intent to kill, injure or intimidate, as well as attempting to bring prohibited fireworks into California, the U.S. Attorney’s Office for the District of New Mexico said.
The jury reached its verdict after deliberating for roughly three hours.
According to prosecutors, Vandenberg was traveling from El Paso, Texas, to San Diego before the June 14, 2025, demonstrations when he stopped at a travel center near Lordsburg, New Mexico, and bought six mortar-style fireworks along with 72 M-150 firecrackers.
During the transaction, federal authorities said, Vandenberg told the clerk he planned to throw the explosives at police officers during the protests.
Prosecutors said he asked several times about how much gunpowder the fireworks contained, whether taping multiple mortars together would make them more powerful, and made clear he was interested only in their potential to injure officers.
Trial testimony also indicated that Vandenberg urged the clerk to go to the protests and distribute fireworks to other people, saying his military background meant he would not be hurt.
The exchange raised enough concern among employees that they recorded Vandenberg’s license plate number and contacted law enforcement before he made it to California.
Federal agents tracked Vandenberg to Davis-Monthan Air Force Base in Tucson, Arizona, where he was arrested the following morning while sleeping inside his vehicle.
Prosecutors said he falsely claimed he was traveling for work despite being unemployed and later told investigators he was visiting friends in Phoenix.
A search of Vandenberg’s vehicle uncovered the fireworks along with clothing displaying antisemitic, anti-Israel and extremist imagery, according to prosecutors.
Among the items recovered were shirts bearing an Al-Qaeda flag, a shirt calling for the destruction of Judea, a hat featuring the Al-Qaeda flag and apparel displaying a variation of the Black Sun, a symbol associated with neo-Nazi ideology.
Jurors were also shown photographs of Vandenberg wearing a custom-made T-shirt bearing the word “AMALEK” while inside the travel center. Prosecutors said Vandenberg told investigators the word meant “destroyer of Jews.”
Investigators also discovered Vandenberg’s cellphone home screen displayed a Taliban flag. A forensic review of the phone uncovered what prosecutors described as violent extremist content, including antisemitic, anti-Israel and anti-U.S. material, as well as messages discussing the upcoming protests.
According to prosecutors, those messages suggested Vandenberg believed the U.S. government, including President Donald Trump, was controlled by Israel and Jewish people, evidence they argued helped establish his motive for targeting law enforcement officers.
“People in this country are free to hold their own beliefs and to express them peacefully,” Acting U.S. Attorney Ryan Ellison said in a statement. “What they are not free to do is use explosives to threaten or terrorize others.”
Ellison added that Vandenberg “intended to turn explosives into a tool of intimidation,” and said the verdict “sends the message that attempts to substitute violence for expressing one’s opinion has no place in our communities and will be met with federal consequences.”
Vandenberg was later sentenced to 16 months in federal prison, where he remains in custody. Upon his release, he will serve one year of supervised release.
