PHILADELPHIA (WPVI) -- There is a new effort to crack several cold cases that have stumped Philadelphia police detectives for decades.Authorities and forensics experts are focusing their efforts on a place known as Potter's Field in the Northeast Philadelphia, where bodies are being exhumed to find answers.Workmen were digging to exhume seven coffins on Wednesday, on orders of local law enforcement authorities.Pennsylvania State Police and the District Attorney are trying to develop leads into a number of cold cases, including a Jane Doe child, 4 to 6 years old, African American who was buried here in 1962 after she was found in a box in the Schuylkill River.Her head amputated, a finger cut off torture style, and she had been severely beaten.Prosecutors want to know more about this tragic case from 56 years ago.Assistant District Attorney Anthony Vocci, Jr. said, "Forget about me being a prosecutor, just as a parent when you have a daughter, you hear a story of this girl whose age we don't know, and no one ever reported her missing. We want to know who she is."There are at least 200 anonymous bodies buried here. Many of the murder victims, all the grave sites marked, but in some cases haphazardly numbered.Many graves as deep as seven feet.The Philadelphia District Attorney says they are using cutting-edge technology from the University of South Florida that will reveal far more about these long-dead anonymous souls buried without the dignity of a name.University of Florida forensic anthropologist Erin Kimmerle said, "We take DNA samples and send it to the lab to get profiles to compare to missing persons then we do isotope analysis of elements that end up in your bones, taken from food and water you ate and drank that can be referenced to broad geographical areas."------