After police were tipped off about potential wrongdoing at a historic cemetery outside Chicago, they found a large back lot strewn with hundreds of cast-off coffins, smashed sepulchers and old bones.

Four employees of the Burr Oak Cemetery in Alsip, Ill., have been charged in connection with the grave scheme, which entailed wrongfully exhuming old plots and selling them as new.

As the freshly re-bereaved flood the grounds to check on family sites and law enforcement agencies investigate the cemetery's sparse paper trail, a handful of forensic anthropologists are winding their way through the weedy back lot to assess the crime's scope.

The first step for them, says Chicago-based FBI Special Agent Ross Rice, will be to identify and locate all of the human remains, which is no small task. The ad hoc open grave—now an active FBI crime scene—is a large one, measuring about 1,600 by 150 feet and could hold several hundred bodies, Rice explains. But estimates are still difficult because grave site contents were tossed in with overgrown vegetation, topsoil and other debris.

Even pinpointing the age of the discarded remains has been difficult, Rice says: "A lot of the records were destroyed." News reports have noted that the schemers may have targeted older graves that received few visitors, which could make examination even more difficult as telling tissue disintegrates over time.

The older subjects, coupled with lack of records and the casual commingling of remains, means that DNA testing would probably be the only way to identify individuals, Rice notes, although he didn't confirm any public plans to proceed with identification at this point in the investigation.

Clyde Snow, a forensic anthropologist who has examined high-profile subjects from King Tutankhamen to Oklahoma City bombing victims, has already made a trip to the site, reported the Chicago Tribune, where he noted that "everything was consistent with what you would see when you disturb coffin burials." He estimated from looking over bones from the site that many had probably died within the last half century, which means that they could still prove useful for DNA tests. But even given the reliability of the method, analysts will still need genetic references—in the form of saliva or hair from relatives of the deceased—to gather results, Snow told the Tribune, a process which will be a long and intensive.

"We're going to be here for a long time—weeks, months," Cook County Sheriff Tom Dart said about the ongoing investigation at a press conference earlier today.

Among the remains inhumed in the cemetery are those of teenage civil rights icon Emmett Till (whose 1955 murder helped spark the civil rights movement) and blues singer Dinah Washington.

The employees, including the plan's alleged leader, cemetery manager Carolyn Towns, have been charged with dismembering a human body—a class 10 felony—and face up to 30 years in prison if convicted.