The deadly attack and the shocking videotape prompted several large marches and prayer vigils in Jackson, a city of about 537,000 people.

Eventually, six white teens involved in that incident pleaded guilty to federal hate crimes for the attack on Anderson and for numerous other attacks on African-Americans. The driver of the truck also pleaded guilty to state murder and hate-crime charges and was sentenced to life in prison.

Hinds County District Attorney Robert Shuler Smith, an African-American, was the prosecutor in the Anderson case. In the case of Johnny Butts, the prosecuting district attorney, John Champion, is white. Many African-Americans in northern Mississippi say they believe the district attorney in the Butts case is not pursuing a hate crime because of his race.

Champion told CNN that there is "no evidence at all" that Darby killed Butts out of hate, or as a hate crime. One reason a hate crime has been ruled out, Champion said, is that the teens in the car that morning could not see whether Johnny Butts was black or white.

But that is not true, according to the statements given by one of the teens in the car. In grand jury testimony obtained exclusively by CNN, Tony Hopper Jr., who was riding in the back seat, testified that he could see Johnny Butts was black before the teens hit him.

"Could you tell whether he was a black man or a white man before ya'll hit him?" Hopper was asked by the grand jury.

"Yes," Hopper said. "I could tell that he was black."

Hopper said the same thing on the day after the killing, when a sheriff's deputy asked him: "Did y'all know if he was black or white?"

Hopper answered: "I could tell he was a black man."

The 15-year-old passenger in the car, riding in the front seat, says in his statement he couldn't tell whether Butts was black or white. CNN's policy is not to identify juveniles in criminal cases.

In an interview that aired on local CNN affiliate ABC 24, Tony Hopper's mother said, shortly after the incident: "It was racist and two of those kids freaked out and couldn't do anything to get out of the car."

Hope Hopper has since said nothing else publicly about it. She did tell local media that after speaking out, she and her family received death threats. She has declined comment to CNN.

When asked about what Hope Hopper said to local media, Champion said:

"I understand what she said, and I don't know where she got that from. (She) never presented us with any kind of reason to say that it was. I don't have a single piece of evidence to tell me it was race related, including the testimony of the two young men who were in the car."

Champion says, particularly because of the earlier incident in Jackson, his team investigated the question of whether Butts was killed out of hate.

"Certainly it's one of the things we investigated when we began the initial part of this -- was this in fact a hate crime?" said Champion. "The investigators looked -- not only at the facts of the crime -- but at a possible motive. And during the course of the investigation we uncovered absolutely nothing that indicated this was a hate crime."

Champion said he does not know the motive in the case.

"I really don't have to prove motive, it's not one of the elements I have to prove. I think only the driver knows what the motive is. I certainly do not believe in this case it was race related, though," he said.

The district attorney declined to talk about any specifics of the case, and says he's barred by law from talking about the testimony and statements given by the teenagers in the car.

The sheriff's investigators, in interview transcripts obtained by CNN, don't ask the teens many questions about the motive for running over Johnny Butts.

Champion said the investigation has exhaustively looked at the background of Darby and found no racism. Champion says he called in the FBI, which he says agreed race was not a factor.

But the FBI suggested to CNN it isn't so sure. A spokesperson said: "The FBI absolutely considers this investigation to be still open."

Pastor Fred Butts is Johnny Butts' brother. He said his brother never had a negative thing to say about anyone, and he was a strong member of the local community. He taught Sunday school every weekend at his church. He exercised every day with his walk on the road. Fred Butts said he believes more was said in the car before the teens hit Butts, and he said he believes it was a hate crime.

"Actually, I think that those guys saw John walking. And I believe they said 'There goes a "N-word." And I believe that's what make that guy just go turn over there, and just ran over him on purpose. I don't believe that they was just ... I just can't believe no kind of way they could just be driving down the road and intentionally just cut over and hit somebody. On purpose," Fred Butts said.

"But he did do it on purpose. You know, you don't run over a dog on purpose. And this man, walking, exercising, they just cut -- and hit him, and uh you know I just can't see that."