A Gwinnett County teen has still not been formally charged in connection to the murders of her two grandparents, but a friend of the 17-year-old granddaughter told 11Alive he doesn't think she is responsible.

Police are still investigating whether the 17-year-old girl played a role in the bludgeoning deaths of her grandparents Randall and Wendy Bjorge over the weekend. 11Alive was not releasing the girl’s name because she hadn't been charged with a crime and had been in the hospital after what police believe was a suicide attempt.

However, on Wednesday night, police confirmed that 17-year-old Cassandra Bjorge had been charged with their murders.

Friends of the family are still shocked and saddened by the series of violent episodes that ended in a SWAT standoff on Sunday. But Gwinnett County resident Ryan Farmer, a high school classmate of the 17-year-old girl, said he didn’t believe she was capable of killing two people.

“We were really good friends,” Farmer told 11Alive’s Valerie Hoff. “She was a sweet girl she was outgoing she was happy. She got good grades she did well in class, she was like your average schoolgirl.”

Farmer said Cassandra had moved in with her grandparents after trouble at home, and later started dating 19-year-old Johnny Rider.

The teen had difficulty staying out of trouble, though, as police responded several times to the Bjorge residence for the 17-year-old running away, as well as an assault on her grandmother when she was 16.

Prior to her grandparents’ homicides last week, police had responded several times to their residence for the 17-year-old running away, as well as an assault on her grandmother when she was 16.

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Rider was already charged for allegedly beating his sister with a baseball bat and pepper spraying her on Saturday while in possession of the Bjorge’s car. Randall and Wendy Bjorge were found dead in their home later that night. As for Farmer, he said he has a hard time imagining the girl he knew from high school would be involved in a crime like this.

“I can't say for sure exactly what happened, but personally I don't think she did it,” he said.

On Wednesday, a memorial outside the grandparent's home had grown with flowers and condolence messages.

Meanwhile, Rider is behind bars for the attack on his sister, with more charges pending after police complete their investigation.