Alameda teen who allegedly plotted terrorist attack is charged with possessing assault rifle

ALAMEDA — A local teen who was the subject of an FBI counterterrorism investigation two years ago has been arrested and charged with possessing an unregistered assault weapon after police received a tip that he was posing with the gun online, records show.

Keylan Abadia, 18, was charged with two felonies and a misdemeanor related to an unregistered AR pistol, a 30-round magazine, and a scope allegedly found during a police search of his Alameda home. He has been released on $55,000 bail and pleaded not guilty to the charges last month, records show.

When Abadia was just 16, the FBI and Alameda police investigated him for allegedly pledging his loyalty to the terrorist group ISIS and searching online for explosives and illegal firearms as part of a plot to attack a government building, authorities said. The only action authorities took at the time was to secure a gun violence restraining order against Abadia, but they kept an open file on him from then on, court records show.

Last month, the FBI reviewed Abadia’s social media postings and found three photos on Instagram that appeared to show him posing with a gun. That led to a July 17 search of his home where the firearm was found, police said in court filings.

The gun violence restraining order was set to expire in 2027, court records show. Abadia was arrested the same day as the search and Alameda County prosecutors charged him the following day.