"It's completely unclear why they made that determination," said Carrie Brooks, spokeswoman for Mayor Adrian M. Fenty. The city is continuing to investigate.
The girls - ages 5 to 17 - were found Wednesday when deputy U.S. marshals served an eviction notice at the apartment. Banita Jacks was charged with four counts of first-degree murder after reportedly telling investigators that the children were possessed by demons and died in their sleep.
The medical examiner's office said there was evidence that one girl had been stabbed and that the others had markings on their necks and other signs of trauma.
The oldest girl, Brittany Jacks, stopped attending classes in early March. A social worker from the Booker T. Washington Public Charter School went to the home April 30 and called police after she was denied entry, Fenty said.
The social worker reported that after speaking to Jacks she appeared to have mental health issues and "that she was possibly holding Brittany hostage by refusing to allow her to attend school," Fenty said. A police officer who responded also was denied entry, but Jacks told him she was home-schooling the children.
Fenty said social workers visited the home several more times in the following weeks, but there was no answer when they knocked at the door. He said the case was closed May 16 because they believed the family had moved to Maryland after finding an address of a relative they believed she was living with.
By mid-June, however, Charles County officials said they were not able to locate the family and "nothing (was) done to reopen the case," D.C. Attorney General Peter Nickles said.
The family did have relatives who live in Maryland, including Jessie Fogle, grandmother of two of the girls. She told The Associated Press that the family's living situation began to deteriorate in February after their father, Nathaniel Fogle Jr., died of cancer.
Jessie Fogle said she helped them rent an apartment, but they were later evicted and lived out of a van and hotels for several months before settling at the Washington address where the bodies were found.
The grandmother said she tried to see Jacks after her son's death, but no one answered the door and when she returned home, there was an abusive voice mail from Jacks berating her for visiting.
The grandmother said she made another attempt to contact Jacks a few months later, but again no one came to the door.
When she learned what happened to the children, "I just started screaming and hollering," she said. "It devastated me. I had been praying to God to bring them home to me."
A spokeswoman for the D.C. Child and Family Services agency referred all calls to the mayor's office.
Sabrina Brown, vice president of Local 2401 of the American Federation of State, County and Municipal Employees, which represents city social workers, said they are extremely overworked and urged people to look for solutions.
"We just need to talk, not to blame," she said.
It is unclear when the girls died. The city's medical examiner has said the bodies were likely in the apartment for more than 15 days. Jacks has told police that the deaths occurred before a utility turned off her electricity, which prosecutors said was in September 2007, according to charging documents.
Lloyd Nolan, a public defender representing Jacks, said the defense team would have no comment on what Fenty said.
--- Associated Press Writers Stephen Manning and Sarah Karush contributed to this report.
