Officer Luis Vidal, who was off duty at the time of the incident, saw a group of six to eight black teenagers throwing snowballs at a white teenager, a police report said.
When the victim told the group to stop, they converged on him and attacked, police said. One of the group started to punch the victim and attempted to steal his phone, police said.
Vidal then tackled and detained the aggressor, while the rest of the attacking group ran off, police said.
The victim was taken to Stamford Hospital for treatment for a broken nose and several cuts on his face and arm, police said.
The juvenile was charged with second-degree assault, second-degree criminal attempt at robbery, interfering with police and breach of the peace.
The juvenile was remanded to the Bridgeport Detention Center.
Stamford Police were still investigating this incident and will attempt to identify all students involved in the incident.
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