Darius Winters' family say he went to a childhood friend's home on the 2900 block of Morris Street Monday night. That's where three men opened fire.
Detectives believe the shooters thought the 15-year-old was someone else.
"We believe this is a case of mistaken identity at this point in time," said Capt. Jason Smith. "We think he's going to be an innocent victim that was targeted incorrectly."
The teen's grandmother says he was a student at Roxborough High School with a passion for history.
"He didn't deserve that; no kid deserves something like that, to just have their life taken," said Winters' grandmother, LaDonna Thornton.
She isn't just calling for the suspects to have a conscience, but for witnesses to speak up.
"The frustrating part is nobody sees anything, nobody known anything. It's the culture, a no snitch culture. It doesn't make any sense to me," Thornton said.
Friends and family plan to have a vigil for Winters next week.
Anyone with any information in connection with this shooting is asked to call police at 215-686-TIPS.