It happened around 10:30 p.m. on the 2500 block of West Somerset Street in North Philadelphia section.
The entire incident was captured on camera.
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"Fortunately, the incident was captured on police real-time crime cameras. We also found some private cameras in the neighborhood and hopefully those cameras recorded additional angles," according to Philadelphia Police Chief Inspector Scott Small.
Small said two gunmen wearing dark clothing opened fire.
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They fled east on Somerset after the shooting.
At least 12 shell casings were found at the scene.
Officers found the 15-year-old boy lying on the sidewalk.
He had been shot in the chest and was unresponsive.
The teen was rushed to Temple University Hospital where he was pronounced dead.
There is no immediate word on what sparked the gunfire.
The victim has not been identified.
Anyone with any information is asked to call police at 215-686-TIPS.