Feb. 19, 2014 -- A juror in the controversial Florida "loud music" trial says there was no chance from the start of a murder conviction in the shooting of an unarmed teen at a gas station because several jurors were convinced Michael Dunn acted in self-defense.

WATCH: Loud Music Trial Juror Reveals Tense Deliberations

Juror #4 – who asked to be identified simply as "Valerie" – told ABC News in an exclusive interview that the issue of self-defense forced the jury into an immediate deadlock and prompted some shouting matches. Two and then three jurors ultimately believed Dunn, 47, was justified in the 2012 shooting death of 17-year-old Jordan Davis. Valerie, who wanted a murder conviction, says the group knew within the first hour that they would be unable to reach a unanimous decision.

The first thing jurors did when handed the case was turn to page 25 in the jury instructions, she said. The question: Do you believe that Michael Dunn was justified or unjustified in the murder of Jordan Davis?"

SEE ABC NEWS FULL COVERAGE OF THE CASE

"It said if he believed that he had an eminent threat to himself or his fiancee, so that was a thing that those two folks believed – he was frightened and there was no other option for him in regards to Mr. Davis," Valerie said. "The rest of us were 100 percent sure, you didn't have to react [with gunfire], you could have had another option.

"We looked at a lot of evidence – and myself, it was where the gunshots were, the timing. Could he have had other options? To me, [the shooting] was unnecessary."

Dunn never denied that he shot and killed Davis in a gas station parking lot after they got into an argument over loud music. But he pleaded self-defense from the witness stand. Jurors found the middle-aged software developer guilty on four of five charges for shooting at Davis' friends, who were also in the car, as well as firing a gun into a car in the 2012 incident. But the mistrial on the first-degree murder charge for shooting Davis has sparked outrage.

According to Valerie, the jurors who believed Dunn was guilty were split between first-degree, second-degree and manslaughter – but because they were unable to unanimously overcome the issue of self-defense, the jury was deadlocked. The jurors yelled and screamed at each other at one point, but all were respectful of each other's position.

Valerie believes Dunn got away with murder.

"A life was taken. There is no longer a Jordan Davis, and there is only one reason why that is. The boy was shot and killed for reasons that should not have happened," she said.

Valerie believes that Dunn could have rolled up his window, put his car in reverse, or simply ignored the loud music blaring from the other car. Despite the disagreement over whether shooting Davis was justified, all the jurors agreed that Dunn escalated the situation by then shooting at the others inside the car, she said.

Valerie decided to come forward after reading and hearing the outrage the verdict generated. She wants the world to know that the jurors valued the life of Davis. Race was never mentioned in deliberations and was not a factor in the decision, she said.

"Folks don't know the law. It's not that we didn't value Mr. Davis life. We had to make a choice," she said.