A 16-year-old "went back to help his friend", but ended up punching a teacher to the ground.
Harwich Youth Court heard the man was left with a broken bone in his face, a dislocated finger and bruising to the ribs.
Dave Deeny, a geography teacher at St Benedict's College, Colchester, suffered nightmares after the incident and has been told by family and colleagues that "he is still not himself", the court heard.
The boy who attacked him, who cannot be named because of his age, was yesterday sentenced to a four-month detention and training order after admitting assault causing actual bodily harm.
David Bryant, prosecuting, said the teenager had gone to the school on January 18 with eight other youths, who were looking for a pupil to pick a fight with after an earlier incident.
Roger Brice, mitigating, said the defendant had left the school premises but "went back to help his friend" who had been grabbed by a teacher.
His behaviour was "wholly and utterly out of character", Mr Brice said.
At an earlier hearing, the second boy admitted being on school premises unlawfully and causing a nuisance. He was given a six-month referral order.
A charge was dropped against another teenager involved in the incident. The 15-year-old had been charged with being on school premises unlawfully and causing a nuisance.
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Published Thursday, February 23, 2006
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