A former North Texas teacher has been arrested in connection with the slaying of her partner nearly three years ago.
Police said they were not convinced because there was no evidence of forced entry.
"Ms. Vaughn, being at the scene, was always one of the suspects, but there just wasn't the information they needed to put together a strong case," police spokesman Corky Brown said.
Investigators said a new piece of evidence allowed them to get a grand jury indictment, but they declined to specify what that evidence was.
Friends of Bell, who was a special education teacher and basketball coach, had all but given up hope that an arrest would be made.
"I was angry," said Denise Roache-Davis, principal of Permenter Middle School, where both Vaughn and Bell were teachers. "A lot of teachers were angry because they felt nothing was being done, that it was a cold case now."
Brown said investigators tracked Vaughn closely since Bell's slaying , even after Vaughn moved to Oklahoma City.
Vaughn was arrested at an Oklahoma City high school where she taught English, Brown said.
Friends and co-workers of Bell said the were relieved to have word of an arrest.
"We're happy that there is a suspect, but we're sad that it was that person," Roache-Davis said.
Vaughn is charged with first-degree murder and is being held in the Dallas County jail.