The 19-year-old murder victim may have said a man's name before she died

After an unknown assailant set 19-year-old Jessica Chambers on fire, the dying teen was left to stumble blindly along a road in Courtland, Mississippi, with burns covering 98 percent of her body.

That’s where she was found later on the evening of Dec. 6, 2014, barely clinging to life. As first responders fought to save her, she reportedly whispered one word: a man’s name, either “Eric” or “Derrick,” according to a source at the scene. It’s a claim that District Attorney John Champion tells PEOPLE he has heard, but can’t confirm. Chambers was taken to a hospital in Memphis, Tennessee, where she later died.

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Was Chambers saying the name of a witness? Or was she naming her killer? Authorities tell PEOPLE her intentions remain a mystery. What authorities do know is that Chambers was in great pain from the gruesome attack. The fire had been so fierce that it turned her black car white, incinerated her clothes, and blinded her. Doctors couldn’t even insert a breathing tube because her airway had been so severely damaged.

For more on the mysterious case of Jessica Chambers, including a timeline of her last day and new information from police, pick up this week’s copy of PEOPLE.

Early attention centered on Ali Alsanai, an attendant at the gas station where Jessica was last seen alive, but security-camera footage quickly cleared him of any involvement in the crime. Despite that, he was forced to leave town after he started getting death threats.

More than a year later, the case remains frustratingly unsolved, but Champion says that his office continues to aggressively uncover what happened on the night Chambers was attacked. Earlier this month, they arrested 17 suspected area gang members on gun, drugs, and counterfeit charges.

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“I don’t anticipate any of these [arrests] being directly tied to the Chambers case,” Champion tells PEOPLE. “But in their plea negotiations, all will be given the opportunity to help themselves – and maybe that will bring us closer to the truth.”