An argument began after Dunn told them to turn the music down, police said. One of Davis' friends turned the music down, but Davis then told him to turn it back up.
According to authorities, Dunn became enraged and he and Davis began arguing. One person walking out of the convenience store said he heard Dunn say, "You are not going to talk to me like that."
Dunn, who had a concealed weapons permit, pulled a 9 mm handgun from the glove compartment, according to an affidavit, and fired multiple shots into the SUV, striking Davis in the back and groin.
Dunn later told police he felt threatened. His attorney has said Dunn saw a gun and shot in self-defense, perhaps laying the ground work for a case under Florida's "stand your ground" law.
If the case sounds familiar, that's because it has echoes of a trial that received wide attention and happened only two hours away.
George Zimmerman fatally shot Trayvon Martin, an unarmed black teen, in Sanford in 2012. Zimmerman, who is Hispanic, was acquitted of second-degree murder in July 2013. He was prosecuted by Jacksonville's State Attorney Angela Corey, who will also be prosecuting the Dunn case.
Zimmerman, a neighborhood watch volunteer, said he believed Martin was acting suspicious. Martin and Zimmerman got into a fight and Zimmerman said he thought Martin was reaching for his gun. Authorities didn't arrest Zimmerman for more than a month after the shooting.
Like Zimmerman, Dunn said he felt his life was in danger when he fired the fatal shots. But unlike the Zimmerman-Martin case, several people say they witnessed Dunn shooting Davis, and that there was no physical scuffle beforehand.
And while Zimmerman stayed on the scene after the shooting and was not immediately arrested, Dunn was tracked down by police and arrested a day later.
According to Jacksonville Police, Dunn fled with his fiancée and drove south more than two hours to his home and never called them. They arrested him the next day after tracking him down through his license plate number.
Dunn told officers that Davis threatened him and he thought he saw someone point a shotgun at him from inside the SUV or maybe it was a stick to make him think it was a gun. Under Florida's self-defense law, Dunn could fire if he believed his life was in danger.
But police recovered no weapon from the crime scene, and witnesses said they never saw a weapon. There was no surveillance video taken outside the store.
In a letter to WJXX in Jacksonville, Dunn told the TV station that the case "has never been about loud music."
"After multiple threats of death by Jordan Davis and his brandishing of a weapon, I was convinced that my life was in danger ... I had no choice but to defend myself, I am NOT a murderer. I am a survivor," Dunn wrote.