An Elk Grove boy who provided care to his disabled mother has been accused of beating her so severely that she required hospital treatment, authorities said Wednesday.

The boy, 11, is in juvenile hall facing charges of assault with a deadly weapon and elder abuse, said Elk Grove police spokesman Christopher Trim. The mother, 51, has been referred to Sacramento County Adult Protective Services. The Bee is protecting the identity of the mother and son because of his age and her disabilities.

Trim said the case is one of the most unusual he has seen during his veteran career as a police officer.

"I cannot recall a case in which a kid has been taken into custody on charges of abusing a parent who has fiduciary responsibility for the child," said Trim. "Typically the situation is reversed. A kid will go to school with marks or bruises, and someone calls police and the parent is arrested."

Trim said the boy and his mother lived by themselves in the home near Bruceville Road where the abuse allegedly happened. A "third party" alerted police to the suspected abuse, Trim said. After visiting with the mother and talking to the son at nearby Foulks Ranch Elementary School, officers arrested the boy Monday.

The mother suffers from a medical condition "which resulted in the juvenile being her caregiver," including doing laundry and cooking meals, said Trim. The boy appears to have primary responsibility for his mother, although "another person does take care of her from time to time," Trim said.

He described the family's home as "fairly presentable" and not in disarray. "There was food in the fridge. Nothing remarkable," he said.

The mother was admitted to an area hospital. Trim declined to discuss details of her disability or the exact nature of her injuries, citing the ongoing investigation. "There is quite a bit more to it, and it's very sad, but there are things I just can't talk about," he said.

"As tragic as it is, fortunately we do not have a death and we can step in and provide resources to the victim and hopefully to the offender as well," he said.

On Wednesday, a man who said he helps the family with cleaning, lawn care and other chores said the mother, who had worked as a claims adjuster, suffers from a range of medical problems.

"She's not hurt from her son," said John Johnson. "She has illnesses," he said, including a history of breast cancer, a foot injury, pneumonia and discoloration on her chest from a bout with skin cancer.

Johnson called her a "nice person who never goes out" and said he has rarely seen the son when working at the home.

It was unclear Wednesday how long the boy had been helping to care for his mother, or whether authorities were aware of the situation.

Laura McCasland, a county spokeswoman, said she was unfamiliar with the case but that child labor laws prohibit anyone under age 14 from working as a caregiver through the In-Home Supportive Services program.

Officers who investigated the abuse report "confirmed that the mother had been beaten on more than one occasion" by her son with an extension cord 8 to 10 feet long and equipped with several outlets, said Trim.

"The mother suffered physical injuries as a result of the child's action" to her arms, legs, feet, chest and groin area, he said. Her medical condition "added to the level of care that she needed" at the hospital, Trim said.

Officers took the electrical cord into evidence. They drove the boy to the Police Department for processing, Trim said, and then to juvenile hall.

The mother likely will qualify for help through Adult Protective Services, a program mandated by the state and designed to ensure the safety of elderly people and dependent adults. APS helps link clients to emergency shelters and community services such as counseling, transportation and meal deliveries.

Program specialist Heidi Richardson said she was unable to confirm whether the woman was a client because of laws protecting privacy.

But if APS did receive such a referral, a social worker would meet with the person and offer a comprehensive range of services, "anything the victim needs or wants from us," Richardson said.