A former Navy SEAL convicted of transporting fireworks across state lines to use against police at a "No Kings Day" protest last year was sentenced Monday to 16 months in federal prison.

Gregory Vandenberg, 49, was convicted by a federal jury in Albuquerque, New Mexico, in January of transportation of explosives with intent to kill, injure, or intimidate, and attempted transportation of prohibited fireworks into California. He was also sentenced to one year of supervised release.

He faced a maximum sentence of 10 years in prison.

Prosecutors said that on June 12, 2025, Vandenberg intended to use explosives against law enforcement in San Diego. Prosecutors said his actions were motivated by extremist, antisemitic beliefs.

Vandenberg was traveling from El Paso, Texas, to San Diego to attend a "No Kings Day" protest scheduled for June 14. While in New Mexico, Vandenberg visited a travel center off Interstate 10 near Lordsburg and bought six large mortar fireworks, which are designed to shoot high into the air and explode, and 72 M-150 firecrackers, which are designed to sound like gunfire, the Department of Justice said in a news release.

Prosecutors said he told the store clerk that he intended to throw fireworks at police officers during the protest. He asked detailed questions about the amount of gunpowder in the fireworks, their explosive impact, and their ability to harm others.

He also discussed taping fireworks together to increase their explosive force. Vandenberg emphasized that he was not interested in the color or display of the fireworks, only in their ability to create explosions and injure law enforcement officers. He encouraged the clerk to join him at the protest and discussed distributing fireworks to others at the event.

Employees recorded his license plate number and contacted law enforcement. Authorities alleged that Vandenberg intended to use the fireworks against law enforcement at the protest, conduct prosecutors said posed a serious risk of injury or death to officers and bystanders.

Federal agents tracked Vandenberg to Tucson, Arizona, and arrested him the following morning while he was sleeping in his car at Davis-Monthan Air Force Base.

Vandenberg initially claimed to be traveling for work, though he was unemployed, and later falsely stated he was visiting friends in Phoenix that weekend.

A search of his vehicle revealed the purchased fireworks, along with clothing displaying antisemitic, anti-Israel, and extremist imagery, including a shirt bearing the al-Qaida flag and another calling for the destruction of Judea. Agents also discovered that the home screen on Vandenberg's phone displayed the Taliban flag.

Investigators further determined that Vandenberg had worn a custom-made shirt bearing the word "AMALEK" to the travel center, which he told investigators meant "destroyer of Jews."

A review of Vandenberg's phone revealed antisemitic, anti-Israel, anti-U.S., and extremist content, including internet searches and messages expressing hostility toward Jews and Israel.

According to court records, investigators found messages indicating that Vandenberg viewed the U.S. government as being controlled by Israel and Jewish people and that those beliefs motivated his desire to target law enforcement officers at the protest. Prosecutors argued that his conduct was driven by extremist, antisemitic views and posed a grave threat to public safety.