The son of Pink Floyd guitarist David Gilmour has pleaded guilty to participating in a rampage during student protests that included an attack on a royal convoy.

Charlie Gilmour was among thousands of students who demonstrated on Dec. 9 against rising university tuition fees. Some protesters broke away from the main demonstration and attacked cars accompanying the Rolls-Royce of Prince Charles and his wife, Camilla.

Judge Nicolas Price warned 21-year-old Gilmour that he could face jail — though he was granted bail until July to give him time to complete Cambridge University exams.

Though Gilmour pleaded guilty to violent disorder on Friday, he did not admit any specific act. Prosecution and defense lawyers will agree on the specifics by June 10.