A 13-year-old girl and her mother were charged with murder Tuesday in connection with the stabbing death of a 15-year-old girl over the weekend in Chicago.

Prosecutors said the 13-year-old, who has not been publicly identified because she is a juvenile, got the knife from her mother, 35-year-old Tamika Gayden. The victim, 15-year-old De'Kayla Dansberry, was stabbed during a fight that broke out Saturday evening in front of a housing complex on the city's South Side.

Cook County Prosecutor Christina Hake, citing eyewitnesses, told a juvenile court hearing that the teen suspect tried to wash Dansberry's blood off the knife when she got home, while repeatedly saying "I killed her. I killed her." An eyewitness told authorites that the girl was "panicking" when she returned home.

The Chicago Sun-Times reported that the mother and daughter turned themselves in to police, accompanied by an attorney.

Prosecutors said that video of the fight existed, but did not elaborate on its origins.

The 13-year-old pleaded not guilty and was remanded into custody by Cook County Judge Cynthia Ramirez. Gayden was charged with murder and felony contributing to the delinquency of a minor.

Dansberry was an honor student and track star at Johnson College Prep, a local charter school. She was scheduled to run in a meet at Eastern Illinois University this Friday.

Dansberry's father, Julian Glanton, said he didn't know what caused the fight.

"I’m sure it was probably just children, like kid stuff," he said. "But it shouldn’t have escalated to where someone was stabbed or anything like that."

"I’m just lost for words," Glanton added. "I don’t know what to say."

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