The shooting happened just before 9 p.m. on August 27 at Academy Park High School on the 300 block of Calcon Hook Road in Sharon Hill, Pa.
A game between Academy Park and Pennsbury High School had just ended when the gunfire erupted near the concession stand. Some 100 to 200 people were leaving the game as the shots rang out.
"That gunfire included a shot in the direction of three Sharon Hill police officers monitoring the crowd exiting the football stadium, which struck and injured a civilian. In response to the gunfire, the police officers discharged their service weapons," Stollsteimer said.
He said there is now a "high probability" that the responsive gunfire from the Sharon Hill Police Officers struck four victims, including the shots that killed 8-year-old Fanta Bility and injured her 13-year-old sister.
"The death of Fanta and the wounding of her sister and the other students are a heart-breaking tragedy for her family, her friends, and the entire Delaware County community," Stollsteimer said.
Officials said the investigation is ongoing. Anyone with information about the individuals involved in the altercation or the initial gunfire is asked to contact authorities.
"My promise to (the family) and to the Sharon Hill community is that we will continue this investigation for as long as it takes until every question is answered and justice is done," Stollsteimer said.