COLUMBIA -- An 82-year-old woman living in a Rock Hill assisted-living home was killed by a nurse's aide at the facility less than a day after she accused the worker of forging her checks, authorities said.

Other nurses at the home found Pauline Cook unconscious in her shower Sunday morning. They attempted to revive her, but she was pronounced dead a short time later, according to authorities and her family.

The coroner called police when she found out investigators had spoken to Cook the day before about someone forging four checks from her account worth $1,200. Cook told investigators she got copies of the checks and noticed they were made out to Braquette Walton, investigators said.

Walton, 30, was charged with forgery on Monday, and investigators added a murder charge Thursday. She was being held without bail.

Authorities won't say how Cook died, but her sister, Jean Robinson, said the family was told she was beaten.

"She had bruises on her arms, where it looks like she was trying to protect herself," Robinson said. "They didn't even have the casket open because they couldn't hide the bruises."

Walton was hired at OakBridge Terrace in July. She passed a background check and received several good reviews from her managers, according to Michael Smith, a spokesman for the facility. A state criminal records check showed only a charge of driving under suspension earlier this year.

Walton was immediately suspended from the home after Cook called police. But she somehow managed to get back inside Saturday night, and administrators at the facility are investigating how Walton was able to return, Smith said.

Robinson went to Walton's bond hearing Friday and said she never looked at Cook's family, instead burying her face in her hands.

Cook went to the assisted-living facility with her husband 11 years ago after he started having trouble keeping up with their house. They first lived in one of the campus' apartments where somebody came by occasionally to check on them or mow their lawn.

Cook's husband died several years ago, and she moved into a building that offered more constant care and monitoring a few years ago as her health declined a little, Robinson said.

But she was still active, visiting with her daughter, granddaughters and Robinson two days before she was found dead. She had no complaints for them and planned to play bingo after they left.

"She loved living down there. She had so many friends and was so happy," Robinson said.