A former US Navy SEAL was convicted by a federal jury on Friday of transporting explosives with the intent to harm law enforcement officials during planned “No Kings Day” protests in California, prosecutors said.
Gregory Vandenberg, 49, was convicted of transporting explosives with intent to kill, injure, or intimidate, as well as attempting to bring prohibited fireworks into California, following a five-day jury trial and around three hours of discussion, according to the Department of Justice.
Prosecutors said Vandenberg was on his way from El Paso, Texas, to San Diego, California, to attend the “No Kings Day” rallies in June 2025 when he stopped in New Mexico to buy six huge mortar fireworks.
“During this visit, he told the store clerk that he intended to throw fireworks at police officers at the upcoming protests. He asked detailed questions about the amount of gunpowder in the fireworks, their explosive impact, and their ability to harm others,” the DOJ said.
Employees got concerned after Vandenberg repeatedly threatened to hurl fireworks at police and inquired whether the business would monitor him, causing them to capture his license plate and contact law authorities.
He was arrested in Arizona after federal authorities discovered apparel with antisemitic, anti-Israel, and extremist insignia, including a t-shirt with a picture of the Al-Qaeda flag.
An investigation of his phone revealed communications indicating Vandenberg was angry at the US government, particularly President Donald Trump, because he believed the country was controlled by Israel and Jews.
“People in this country are free to hold their own beliefs and to express them peacefully,” said Acting U.S. Attorney Ryan Ellison. “What they are not free to do is use explosives to threaten or terrorize others. Vandenberg intended to turn explosives into a tool of intimidation, and this 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.”
The DOJ stated that the court ordered Vandenberg to remain in detention pending his sentencing following the verdict, which has yet to be scheduled.
He risks ten years in prison.