A 14-year-old boy has been charged with shoving a Methuen police officer, breaking his shoulder and cutting his head.
Police say the officer was responding to a center for troubled youth on Tuesday when the incident happened.
They say three teens were trying to leave without permission when one of them shoved the officer into a fence.
All three boys were taken into custody.
One of them was charged with assault and resisting arrest.
It is unclear if the suspect has an attorney.