Nearly 100 years after a race massacre left hundreds of black people dead, Tulsa began searching for evidence that victims of one of the country’s worst episodes of racial violence were buried in mass graves.

On Monday, scientists and forensic anthropologists armed with ground-penetrating radar combed the grounds of Tulsa’s Oaklawn Cemetery, looking for anomalies that might be consistent with mass graves.

The cemetery, which is owned by the city, is just a few blocks from what is known as Black Wall Street. It is also the site where, in 1999, renowned forensic anthropologist Clyde Snow led a team of scientists who discovered an anomaly bearing “all the characteristics of a dug pit or trench with vertical walls and an undefined object within the approximate center of the feature,” the Tulsa Race Riot Commission concluded in its 2001 report.

Along with testimony from a witness of the massacre, the report said, “this trench-like feature takes on the properties of a mass grave.” The commission recommended excavation, but the city decided not to dig for physical evidence.

Last year, Mayor G.T. Bynum (R) announced that he would reopen the investigation into mass graves, calling it a murder investigation. The announcement followed a Washington Post story about the unresolved questions surrounding the massacre.

“We owe it to the community to determine if there are mass graves in our city,” Bynum told The Post at the time. “We owe it to the victims and their family members.”

The city is obligated to find out what happened in 1921 as Tulsa prepares to mark the 100th anniversary of the rampage, he said.