Ex-Navy SEAL planned to fire explosives at SDPD at No Kings Day in San Diego: prosecutors

A jury in New Mexico found a former Navy SEAL guilty on Friday of transportation of explosives with intent to kill, injure or intimidate in connection with a plot to fire explosives at police during June’s No Kings protests in San Diego County.

Gregory Vandenberg, 49, first came to law enforcement’s attention in connection to the case when he stopped at a travel center near Lordsburg, New Mexico, on June 12, 2025. According to federal prosecutors, he bought six large mortar fireworks, as well as 72 M-150 firecrackers, which, investigators said, mimic the sounds of gunfire.

While shopping for the fireworks, Vandenberg told a clerk he planned to throw the explosives at police during the No Kings protest in San Diego two days later. According to prosecutors, he “repeatedly expressed a desire to throw fireworks at law enforcement officials at the protests in California.”

“He asked detailed questions about the amount of gunpowder in the fireworks, their explosive impact and their ability to harm others,” the U.S. Attorney’s Office for the District of New Mexico said in a news release sent out on Monday. “He also discussed taping multiple fireworks together to increase their explosive impact.”

Vandenberg reportedly told the clerk he did not care about what displays the fireworks made, only about their explosive potential, prosecutors said.

Workers at the rest-stop store were, understandably, concerned about their interaction with Vandenberg and shared his license plate number with law enforcement, which eventually caught up with him in Tucson at Davis-Monthan Air Force Base, where he was located sleeping in his vehicle, which he was living out of.

Investigators said they found the fireworks in his vehicle, as well as a T-shirt with an Al-Qaeda flag on it and another “calling for the destruction of Judea.” They found a third shirt, this one bearing the word “Amalek,” which Vandenberg said meant “destroyer of Jews” he was wearing at the rest stop when he bought the fireworks.

“A review of his phone also showed messages suggesting Vandenberg was upset with the U.S. government, including President Trump, because he viewed the U.S. government as being controlled by Israel and the Jews,” prosecutors said in the news release.

Vandenberg was also found guilty of a lesser charge of attempted transportation of prohibited fireworks into California. He faces up to 10 years in prison at sentencing, which has not yet been scheduled.