The killer claimed the stabbing was accidental, but the prosecutor said, "There is no arguing what her intent was"

Texas 14-Year-Old Was Fatally Stabbed by Friend, Who Said Victim 'Was Like a Sister to Me'

A Texas teenager was convicted Thursday of fatally stabbing her 14-year-old friend in 2018, when the suspect was 13, PEOPLE confirms.

A Tarrant County District Attorney’s Office spokeswoman tells PEOPLE that the killer, now 14, was found guilty of delinquent conduct in juvenile court, which is equivalent to murder in adult court.

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The victim, Nylah Lightfoot, died last May 29 from stab wounds to her neck and chest, Fox4 reports.

The Fort Worth Star-Telegram reports the killer, who is not publicly identified because she’s a minor, called Nylah “the best friend anyone could ever have” while testifying, and said the victim “was like a sister to me.”

But NBC5 reported last June that Lightfoot’s mother Anntoinette Carter said the pair had an on-and-off relationship, adding, “Now, I’m daughterless. My heart feels like it’s been ripped out and stomped on.”

According to her killer’s testimony, she and Nylah spent the day together with two other girls, the Star-Telegram reports. The day began at a pool party before the group went back to Nylah’s apartment, where they listened to music, danced and posted videos to Instagram.

But then Nylah and her killer got into a fight, leading to the fatal confrontation.

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The killer testified the stabbing was accidental, saying the two were fighting and she went to grab a knife to scare her friend, the Star-Telegram reports.

“She walked up on me and said, ‘Stick me, stick me, I want to die anyways,’” the teen testified. “She ran up on me and she swung at me and I reacted. My intent was never to harm her. She was my friend.”

But Tarrant County prosecutor Jim Hudson said the teen intended to hurt Nylah and had previously threatened her.

“There is no arguing what her intent was,” Hudson said, according to the Star-Telegram. “When she came outside with the knife she was still in control. But not even her friend could stop her. She was only following through with what she had threatened twice.”