She had returned to Philadelphia because she wanted to die in the house she had owned for more than 40 years. Suffering from congestive heart failure, Carter moved in with her son and his teenage children around September, police said, and was completely dependent on his care.
Police said Bullock fed the woman only once a day and forbade his children from providing her with any food or water. He stole - and sometimes sold - her $7 Meals on Wheels dinners, police said.
He stopped changing her diaper and would scream curses and Bible verses at her, often calling her a sinner, they said.
Bullock's abuse was observed by a home health-care nurse, who visited three to four days a week for several hours a day, police said.
Eventually, Bullock had his electricity turned off despite the health-care worker's pleas that his mother's oxygen tank relied on the power.
The nurse told police she had tried to persuade Peco workers not to shut down the power, but they told her the account was in the son's name, so they had to do as he asked. Peco spokeswoman Cathy Engel Menendez said she could not comment on any specific case, but said the utility's policy is to confirm with a customer that turning the power off would not adversely affect a resident.
The nurse was able to keep Carter alive with a nonelectric oxygen tank, police said. She was removed from the home by the Fire Department and placed in protective care in October. She later succumbed to her illness, police said.
For months, the Police Department's Special Victims Unit and the District Attorney's Office have been investigating the case.
Citing the son's abuse and neglect, prosecutors on Thursday charged him with attempted murder.