PIKEVILLE, Tenn. - Bledsoe County authorities say a woman's daughter-in-law gunned her and her sister down, they're just not sure why.
But one official noted that both sisters recently had changed their wills.
"It is something that we've looked at [in trying to determine a motive]," said Assistant District Attorney Jim Pope.
Elizabeth Brown, 82, and Billie Sue Blaylock, 79, both were shot once in the face, authorities said.
Brenda Brown, 47, who attended the sisters' funeral on Aug. 19, was arrested Wednesday and charged with two counts of first-degree murder, Bledsoe County sheriff's investigator Ricky Seals said.
On the same day, officers searched her home, which is right behind the house where the slain sisters lived, Bledsoe Sheriff Jimmy Morris said.
Some items from the sisters' home were found in trash at Brenda Brown's home, said Seals, declining to say what those items were.
"Actually, that was what broke the case for us," he said.
Brenda Brown, a mother of two, is being held without bond at the Bledsoe County Detention Center and is scheduled to appear in General Sessions Court this morning, according to jail officials.
She originally was brought in for questioning after she called 911 on Aug. 16 and said she'd found the bodies, Morris said.
The motive is under investigation, he said, but evidence points to Brenda Brown.
He said he's at a loss to explain a reason for the killings. There had been no disagreements between Brenda Brown and the sisters, he said.
"[Brenda Brown] took care of these ladies," he said. "She took them to the doctor."
Morris said Brenda Brown was interviewed three separate times before her arrest.
Elizabeth Brown's son, Bill, has not been implicated in the killings, Seals said.
Seals said Bledsoe County officials and agents with the Tennessee Bureau of Investigation served a search warrant Wednesday night at Brenda Brown's home, where they recovered a .40-caliber Glock semiautomatic handgun.
"That's going to be the weapon we believed was used," Seals said Thursday.
Authorities said the gun was hidden in the home's attached garage.
Brenda Brown has been in trouble before and is on probation from a sentence handed down in 2010.
In July 2009, she was arrested on felony charges of aggravated burglary, theft over $10,000 and vandalism over $500 for a break-in at the home of Bledsoe County residents Houston and Karen Thomas, according to Circuit Court records.
Last August, Brown pleaded guilty to all counts, earning a sentence of four years and 10 days from Bledsoe County Circuit Court Judge Curtis Smith, records show. Smith ordered Brown to serve four years of the sentence on probation and ordered her to serve the remaining 10 days in jail, 24 hours at a time, over 10 weeks.
The investigation into the Brown sisters' deaths is continuing, but Morris and Seals said they don't anticipate any more arrests unless something new develops.
A first cousin to the sisters, Ed Frazier, said the family was stunned by the arrest.
"It's just unbelievable," a shaken Frazier said Thursday afternoon. "We just can't fathom a thing like this happening in our family."
Frazier said he is most concerned about Brenda Brown's children, an adult daughter and younger son.
"They have to live with this the rest of their lives," he said. "That's a hard one right there."
The peaceful community has been shattered along with the family, he said, and his neighbors now are locking their doors, talking about buying guns.
"People are asking me, 'Do you think she did it?' I don't know," he said. "I just don't know."