DALLAS – An honors student has been charged with delivering marijuana-spiked muffins to a teachers lounge in a senior prank that sent 18 people to the hospital and triggered FBI and terrorism investigations.

“I had no idea of the scope of my actions,” Ian Walker, 18, said Friday, a day after he and friend Joseph Tellini surrendered to police. They could receive 10 years in prison or more if convicted of felony charges.

Walker is accused of bringing the muffins to Tellini’s suburban school May 16 and claiming they were part of an Eagle Scout project. When Lake Highlands High School employees ate the muffins, they began complaining of nausea, lightheadedness and headaches.

Most of those sickened were quickly treated and released, but an 86-year-old receptionist spent two days in the hospital.

The FBI investigated because the case involved contamination of the food supply at a school. A joint terrorism task force found that terrorism was not involved, but determined the muffins contained marijuana and turned up a surveillance video of the delivery.

Walker, who attends a nearby Catholic school, and Tellini, 18, were each charged with five felony counts of assault on a public servant, each of which carries penalties of two to 10 years in prison. Because of the presence of illegal drugs, Dallas County prosecutors are seeking an upgrade to the charges that could raise the maximum sentence to 20 years, district attorney spokeswoman Rachel Raya said.

The teens were released on $7,500 bail each. Calls to Tellini’s home and attorney were not immediately returned Friday.

Ian Walker’s mother, Caroline, said she first heard about the tainted muffins while watching the news with her son.