Tevin Key, 19, has been arrested in connection with the murder.
He, along with 14-year-old Mackey Jones and 16-year-old Markel Flagler, are charged with killing Tiffany Fletcher.
RELATED: Mother of slain Philadelphia rec center worker wants killer 'put away for life'
She was caught in the crossfire of a shootout involving Jones outside the Mill Creek Rec Center on the 4700 block of Brown Street.
The rec center is now named for her.
She left behind three children.