The 10-year-old, who lives just up the block from victim Minh Tran, was charged as a juvenile with aggravated assault, criminal trespass, and related offenses, according to the District Attorney's Office.
Police are still investigating the identities of the two other boys, said Gallagher, whose unit is handling the case.
"This 10-year-old torments her in the neighborhood," Gallagher said. "He's tried to do things to her before in terms of harassments and threats. . . . He chases her and confronts her."
Tran lives in a well-kept apartment attached to the house of Pastor Dao Tien of Vietnamese Alliance Church, who owns the property on the 1200 block of East Luzerne Street. The apartment was converted from a garage when Tien's family took in Tran.
It is unclear when the harassment began or what prompted it, but it became routine, Tien said.
Tien's family became a target as well, he said, and boys would often come through the fence into their yard, trashing things or turning on outdoor faucets.
As recently as 8 p.m. Saturday, Tien's mother-in-law called the police because boys were running back and forth outside the house, pounding on the doors.
But the worst abuse was saved for Tran.
Monday evening, the 10-year-old recruited his younger friends, Gallagher said, and around 5:50 they entered her open front door.
"The 10-year-old saw her as a target of opportunity," Gallagher said. "They saw a chance to get in."
Once inside, the boys began to hurt her, whipping her with the rope and hitting her with rocks and sticks, Gallagher said. One boy took a potted plant and threw it at her.
Tran, who does not speak English, told a reporter through Tien that she was all right physically.
At first, she nervously avoided saying what had happened before reluctantly stating that "they came and they beat me up." Tran used the jump rope to demonstrate how one boy stood over her and whipped her with it, before pointing to a stick that she said had been broken during the attack.
The boys rifled through her cabinets, looking for money that was not there, according to Tran; eventually, they took her purse and $20.
Tien said that another family on the property, hearing Tran's screams and cries, brought the boy's mother over, who immediately said to call the police.
The mother was extremely cooperative, Gallagher said, and told police that she had suspected her son of being involved.
He has been impossible for her to control, Gallagher said, and she suspects him of other crimes in the neighborhood. The family declined to comment.
Tran had cuts and bruises to her face and cuts and scrapes to her legs, and complained of head and chest pain, police said. Later Monday night, Tien said, he took her to Temple University Hospital for treatment.
The 10-year-old was being held Tuesday night at the Youth Study Center with a hearing scheduled for Aug. 27 in Family Court.
In addition to aggravated assault and criminal trespass, the boy was charged with simple assault, conspiracy, possession of an instrument of crime, theft, recklessly endangering another person, robbery, and burglary, according to Tasha Jamerson, a spokeswoman for District Attorney Seth Williams.
According to Jamerson, Pennsylvania allows for the criminal prosecution of children under 10 only in cases of murder.
Contact Jonathan Lai at 215-854-5151 or firstname.lastname@example.org, or on Twitter @elaijuh.
Inquirer staff writers Hai Do and Robert Moran contributed to this article.