Mr. DeSantis has asked state officials to work with Jackson County on how to address the new findings, and more testing is needed to determine whether the anomalies are, indeed, unmarked graves. The county plans to develop an industrial center at the site as well as a training center for people with autism.

Almost from the moment the school opened as the Florida State Reform School in 1900, there was a steady stream of reports of abuse, indentured servitude, crowding and neglect. So many children — among them runaways and so-called incorrigibles — were sent to the institution that it became the largest in the country.

Despite continued allegations of mistreatment and harsh conditions, the school remained open until 2011, when the state shuttered it. Advocacy efforts by a group of men known as the White House Boys helped to reveal the horrors that took place at the school. A team of anthropologists from the University of South Florida used radar technology to search beneath the ground and discover dozens of unmarked graves.

The anthropology team has focused largely on Boot Hill, which during the segregation era was a documented cemetery on the African-American side of campus.

The latest findings only add to the catharsis for people like Jerry Cooper, who was at the school from 1960-61 and is president of the White House Boys, whose name is a nod to the small cinder-block building where they say they were viciously flogged for the slightest infraction.