At the time, a 10-year-old boy, previously described by police as "the ringleader," was arrested and uncooperative with authorities. Since that boy was charged, Sheeron said, police no longer have contact with him. The identities of the other two boys were unknown at the time although police said one could be as young as 7.
The investigation is still ongoing, but the police now believe they have the second boy's identity. The identity of the third boy, believed to be between the ages of 9 and 12, is also being investigated.
"We have some names that we're investigating," Sheeron said. "We have some good ideas."
All three boys under investigation are from the same neighborhood, Sheeron said.
Police talked to Tran through a translator. An ethnic Chinese who was born and raised in Vietnam, she came to the United States in 1999.
If the identity of the 7-year-old boy is confirmed, Sheeron said, his case would likely be referred to the Department of Human Services.
In Pennsylvania, criminal charges can only be brought against children under the age of 10 in cases of murder.
The 10-year-old boy was charged as a juvenile with aggravated assault, criminal trespass, simple assault, conspiracy, possession of an instrument of crime, theft, recklessly endangering another person, robbery, and burglary, Tasha Jamerson, a spokeswoman for District Attorney Seth Williams, said last week.
Contact staff writer Jonathan Lai at (215) 854-5151, firstname.lastname@example.org, or on Twitter @elaijuh