Detectives say the violence started after an altercation between a group of teens.
Behind a maze of yellow crime scene tape, East Detectives marked bullet casings inside the Fairhill Square Park at 4th and Lehigh Avenue, at least 15 shots were fired.
Captain Drew Techner said, "We had received reports that there were young juveniles inside the park and there was some sort of confrontation or commotion.
That altercation triggered a barrage of bullets just after 7 Saturday night.
The teen was hit once in the left side of the chest. Witnesses say the 17-year-old boy ran into a row home for help.
A family member confirmed the teen lives there, but declined to talk on camera.
A 21-year-old, who witnesses described as the shooter was arrested at the scene.
"There was at least one person more likely based on ballistic evidence recovered at the scene. At least two people firing gunshots from inside the park," said Captain Techner.
But what's not clear is if the 17-year-old was the intended target and if he and if he had a prior history with the men who pulled the trigger.
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