In the first major prosecution to come out of the disaster, Salvador A. Mangano and his wife, Mable, were accused of failing to adhere to evacuation plans drawn up for St Rita's Nursing Home, in Chalmette, which was housing 60 elderly residents when the hurricane hit.
Instead the couple, who are now in custody awaiting their next court hearing, stayed at the home with the patients, a decision the Attorney General of Louisiana, Charles C. Foti, called "pathetic".
They had turned down offers from officials in the area who asked if the nursing home needed any transportation to evacuate the patients, he said.
"They didn't follow the standard of care of what a reasonable person would follow," Mr Foti said. "The pathetic thing in this case is that they were asked if they wanted to move and they did not move. They were warned repeatedly that the storm was coming. In effect, their inaction resulted in the deaths of these patients."
Each count of negligent homicide carries up to five years in prison. The attorney general was also investigating the discovery of at least 44 corpses found at the Memorial Medical Center, in New Orleans, on Monday. The bodies have not all been identified and he was not sure how many of the victims were patients or staff, he said.
The first British fatality from the hurricane was confirmed by the Foreign Office yesterday.
A spokesman said the unnamed victim was a long-term resident of New Orleans, and that their family was also resident in the area.