A grand jury investigation into deaths at a hospital during the chaotic aftermath of Hurricane Katrina will not begin for at least a month.

Orleans Parish District Attorney Eddie Jordan said Thursday it would take that long for the coroner's office to present its findings, including autopsy and toxicology reports and an official classification of the deaths.

Click here to visit FOXNews.com's Crime Center.

Dr. Anna Pou, a cancer and ear, nose and throat specialist, and nurses Cheri Landry and Lori Budo, are accused of being principals to second-degree murder in the deaths of four patients at Memorial Medical Center.

The attorney general accuses the three of giving lethal amounts of morphine and a sedative to acute care patients who might have otherwise survived, killing them three days after the storm.

Through attorneys, the women have said they are innocent and are being made scapegoats after being stranded for days without electricity, running water or communications in a hospital flooded with 10 feet of water.

Click here to read the charges against the hospital workers (pdf).

They were arrested July 17 and released without bond. The grand jury will decide on formal charges.

Thirty-four people died at Memorial during the crisis. Some of those deaths still are being investigated.