One of the accused attackers, Emmanuel Benjamin Boykins, 18, told Channel 2 Action News Tuesday that a look from Tillman sparked the brawl. Boykins said he asked Tillman, "What are you looking at?" and Tillman responded "What are you looking at?"
Although he acknowledged being part of a group that then began beating Tillman, Boykins denied responsibility for his death. Boykins also singled out another of the accused, Horace Damon Coleman, 19, as being innocent.
His account conflicts with statements from others who were present, who said Boykins picked out Tillman from a distance and attacked him with no warning and no words having passed.
As authorities worked to sort out the events surrounding Tillman's grisly death -- including suggestions that more than four men were involved in the attack -- an often profane debate was already raging on Facebook between defenders of the four accused teens and those outraged by Tillman's fate.
In addition to Boykins and Coleman, Quantez Devonta Mallory, 18, and Tracen Lamar Franklin, 19, have been charged with murder and are being held without bond at the Douglas County Jail.
According to witnesses, Tillman was attacked as he and a group of teens tried to leave a house party on Independence Drive in Douglasville Saturday night. The witnesses said the incident began as a spat between two girls, one of whom struck a boy, who angrily declared that while he would not hit a girl, he'd hit the next boy he saw.
That boy was Bobby Tillman, whose fatal beating was over in a minute, witnesses said. Tillman, who graduated from Chapel Hill High School, didn't know his attackers, who went to Douglas County High School.
In addition to the brutality of the attack, McDade played up Tillman's reputation as a gentle person and a conscientious student.
"Everything that I’m being told was he was a sweet young man destined for greatness," McDade said. "The kind of kid you'd be proud to raise."
However, the prosecutor declined to say that he would seek the death penalty, although he said he was getting many calls urging him to do so.
"I must wait until the investigation is much further along," he said via e-mail. He added, however, that "from what I know at this point it certainly has aspects that many other death penalty cases have."
Tillman, who was 18, was studying to be a sports agent at Georgia Perimeter College. His mother, Monique Rivarde, said she moved her family to Georgia two years ago to escape the dangers of Los Angeles.
Social media outlets continued to swarm with news of his death Tuesday, with Facebook groups memorializing the teen while others defended his accusers.
A fan page in Tillman's remembrance had more than 7,000 members by Tuesday afternoon, with friends and strangers alike sending condolences to his family. People from across the country plan to wear black Friday to remember the teen.
Another page, titled "Freeee [sic] Horace Coleman," defended the accused attacker and had such comments as "he would neva [sic] do sum [sic] like this."
Some of the comments on that same page suggested more people were involved in the attack. One person said indicated that she knew others who were involved and pleaded for people with more information to contact authorities.
McDade said his office is looking into leads on the social media sites and continues to interview neighbors and witnesses. He's investigating the possibility that more people were involved.
But Tuesday evening, as mourners gathered at Chapel Hill High for a candlelight vigil, Tillman's family was focusing on the memories of the gray-eyed teen, who was looking forward to having his braces removed in the spring.
They've established a fund in his honor through Bank of America. Tillman will be buried Saturday at Siloam Church International in College Park.