A 14-year-old girl from the small town of Mundelein, Illinois, has been charged with murdering her little sister by stabbing her to death.
Dressed in gray detention centre scrubs, her brown hair pulled into a ponytail, the girl remained passive in the juvenile court hearing room until Lake County Assistant State's Attorney Claudia Kasten recounted how the teen allegedly fetched a kitchen knife, the weapon used to stab her 11-year-old sister to death.
The teen's face flushed and her eyes brimmed. The woman sitting beside her, mother to victim and accused, blinked slowly and began to cry. But never did mother and daughter break their gaze from the judge sitting across the table. Never did they share so much as a glance.
The bleak scene came as prosecutors tried to explain how a sibling argument exploded into lethal violence on Tuesday morning, when the 14-year-old allegedly stabbed her sister dozens of times in a fury over the child's supposed ingratitude.
Multiple sources and public records, including her parents' divorce file, identify the victim as Dora Betancourt.
"This is quite a tragedy ... There's a lot of grief going on right now," Mundelein Mayor Steve Lentz said at a news conference. "Please pray for us."
Authorities did not offer much information on the sisters' relationship, but the Facebook page belonging to the 14-year-old — who has not been named because she has been charged as a juvenile — shows the two smiling together in several photographs.
"They would play in the front yard often," said neighbor Matthew McCoy, who lives a few doors down on Woodhaven Court. "The oldest girl would help the young girl do cartwheels."
Dora attended St. John Lutheran School in Libertyville. Her family has been a member of St. John Lutheran Church for years, said Steven Fuoco, a lawyer for the school and church.
Liam Welch, 14, went to elementary school with the 14-year-old girl and got back in touch in recent months. He said the alleged attack was utterly out of character for his friend, whom he described as funny and caring.
"If somebody at our school was having a really hard time, she was always there for them to make them feel better," he said.
While many questions remain about the alleged attack, Lake County prosecutors offered an unsettling account of its origin and aftermath.
This is quite a tragedy ... There's a lot of grief going on right now. Please pray for us.
During police questioning, the 14-year-old allegedly said that Dora had been hitting her and was not appreciative of her efforts to keep the household running. The girl said she had cooked dinner at least six times the previous week along with other chores, the prosecutor said during the court hearing.
Officials said the girls' mother was the only adult living in the home. She was at work on Tuesday morning, they said, when her daughters' quarrel took a horrifying turn.
Kasten said the 14-year-old, still angry over the previous night's argument, allegedly got a knife from the kitchen and went to Dora's bedroom. She began to stab her sister, saying with each wound inflicted that the younger girl was not thankful for what she had done, Kasten said.
"A struggle ensued," Kasten said. "She kept stabbing."
When the attack was over, Kasten said, the 14-year-old attempted to wash the blood off herself and phoned her mother with a lie: She claimed she had awoken to screams and found an intruder in the house stabbing her sister.
Her mother told her to call police and she did, meeting officers in tears when they arrived minutes later. The teen's hair was wet and she had some blood on her arms, Kasten said.
Dora sustained about 40 knife wounds, mostly around her neck, chest and arms, authorities said. A knife and a green shirt lay on the bed.
The officers did not find an intruder. They took the 14-year-old to the Mundelein Police Station, where she repeated her account, but when investigators told her they had found strands of hair in Dora's hand, she changed her story, Kasten said.
The 14-year-old faces juvenile charges of first-degree murder. Lake County State's Attorney Mike Nerheim said he will consider in the weeks ahead whether to prosecute her as an adult.
Mundelein Police Chief Eric Guenther said officers had been called to the family's house before "but nothing that pertains to an incident like this."
Mundelein, a village of about 31,000 people northwest of Chicago, is a relatively wealthy community. It boasts a median family income of more than $US80,000, and the average home price exceeds $US400,000. About 90 per cent of Mundelein High grads pursue further education. It is a place not accustomed to horrendous crimes.
The Illinois Department of Children and Family Services had not had prior contact with the family, but spokeswoman Karen Hawkins said the agency was now investigating the girls' mother for allegations of neglect.
The alleged attack was as unusual as it was shocking. FBI data indicate that among adolescents who kill, boys outnumber girls roughly 10 to 1. In 2012, only 55 girls nationwide committed the crime.
But researchers say that when girls do kill, they are more likely than boys to murder younger victims, frequently family members. They're also more likely to use a knife and to act in the grip of ungovernable anger.
"Multiple stab wounds can indicate rage as well as dissociation," said Kathleen Heide, a criminology professor at the University of South Florida who has researched girls who kill. "That's why a (risk evaluation) is critical. Is this person aware of what she's doing?"
Michael Conway, the lawyer appointed to represent the girl at Wednesday's hearing, told Judge Valerie Boettle Ceckowski he had 29 pages of discovery he hadn't had time to review with his client.
At the end of the hearing, Ceckowski said she decided to keep the girl in custody "based on probable cause and what I've heard."
The girl, impassive again, stood as reporters were ushered from the room. She is due back in juvenile court January 31.