‘Jihadi John’, a masked Islamic State militant seen in gruesome videos of beheadings of Western hostages, received anger management therapy in his first year of secondary school in the U.K. after getting into fights.

Mohammed Emwazi attended Quintin Kynaston School in Queens Park, northwest London, a decade ago.

His former teacher said Emwazi needed help controlling his emotions but he was regarded as a “success story” after the therapy, she added.

“We’d find that he’d get very angry and worked up and it would take him a long time to calm himself down, so we did a lot of work as a school to help him with his anger and to control his emotions,” the teacher was quoted as saying by the BBC.

“It seemed to work. He had a lot of respect for all of the work that had been done for him at our school,” she said.

A statement from Quintin Kynaston School said it was “shocked and sickened” that its former pupil may be involved with Islamic State.

“All members of staff at QK work very hard to support the education and wellbeing of our students and protect them from harm,” it said.

“In this respect, QK has been extremely proactive in working with the government’s prevent strategy for a period of time and will continue to be so for the foreseeable future,” it added.