Police say the victim was shot at the artificial turf sports field on Columbus Avenue just before 11 a.m. and pronounced dead at the scene.
At least three suspects fled the scene.
The victim has been identified as Damel Mitchell, 17 of Roselle.
"This is a startling incident and one that has no place in the city of Roselle or anywhere," said Mayor Jamel Holley. "Anyone who commits a crime in our city will be sought after and punished to the full extent of the law. I ask my fellow residents to be vigilant, report suspicious behavior, and to stand with police against any criminal that seeks to disrupt our peaceful way of life."
No arrests had been made as investigators tried to determine who did the shooting and why.
Anyone with information is urged to contact the Union County Crimestoppers at (908) 654-TIPS or www.uctip.org. Tipsters that anonymously provide information that leads to the arrest and indictment of the person or persons responsible are eligible for a cash reward of up to $5,000.
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