The mother of a 7-year-old boy who claimed a carjacker killed her son was arrested Monday and charged with murder in her son's death, Greenville County Sheriff Steve Loftis said.

Amanda Reagan Smith was arrested nearly three months after she told authorities that a knife-wielding carjacker forced her to drive to a secluded, wooded area in Greenville on Aug. 12. Once there, she said the carjacker locked the car doors and pressed a pillow to the face of her 7-year-old son.

"Investigators have concluded that Amanda Smith is responsible for the death of her son," Loftis said during a news conference in Greenville. "We are confident that we have the suspect in jail now."

It was not immediately clear if Smith had an attorney. A woman who answered the phone at the jail did not know if she had an attorney.

Loftis said during the investigation that Smith always answered questions from police and continued providing tips, though he would not elaborate. Loftis also would not say if she changed her story.

"We had our doubts and suspicious, but we have to follow the tips," Loftis said.

Smith was treated at a hospital and released after reporting the incident to police, telling authorities the scratches on her arm came from a fight with the suspect.

In the hours after the killing, police dogs and helicopters searched the woods where Smith said the attacker had fled. Sketches of a suspect she described were posted in businesses and neighborhoods.

The case revived vivid memories of another mother named Smith — Susan Smith, who in 1994, about an hour east of Greenville, reported that she had been carjacked by a man who escaped with her sons.

Smith went on national television to beg for the boys' safe return. Days later, she confessed to strapping them into their car seats and letting her vehicle roll into a lake, where they drowned. She was sentenced to life in prison.