For decades, relatives of some boys dispatched to the notorious Arthur G. Dozier School for Boys have struggled to find out what became of them after they went missing amid reports of beatings, torture and sexual assaults at the reform school in Marianna, Fla. On Tuesday, researchers and forensic anthropologists moved a step closer to providing answers.

The remains of 55 people have been uncovered on school grounds, University of South Florida researchers announced – five more than previous field work had indicated and 24 more than listed in school records. "Locating 55 burials is a significant finding, which opens up a whole new set of questions for our team,’’ said Erin Kimmerle, a University of South Florida associate professor and forensic anthropologist who has led researchers on a nearly two-year project aimed at uncovering lingering mysteries at the school, which operated from 1900 to 2011.

From September to December of last year, researchers led excavations at or near Boot Hill, an unmarked cemetery on school grounds. Using ground-penetrating radar, DNA samples and search dogs, they probed for unmarked graves of boys reported missing over the years. Bones, teeth and other artifacts were recovered for all 55 bodies, Kimmerle said Tuesday. Bone and teeth samples will be submitted for DNA testing.

Meanwhile, researchers are attempting to collect DNA from survivors of boys sent to the school as "incorrigible,’’ or for truancy or petty crimes. So far, DNA has been collected from 11 surviving family members of former Dozier residents. Researchers are seeking DNA from 42 more. Anyone with information may call the Hillsborough County Sheriff’s Office at (813) 247-8678. The grave sites are not marked; some remains have been found in woods nearby. Thirty-one white crosses that dot the burial ground were erected in the 1990s to commemorate the unnamed boys buried there.