JACKSONVILLE, Fla. -- For the first time Michael Dunn explains in detail what he said happened the night the Jacksonville teen he is accused of murdering was shot to death.

On Monday the State Attorney's Office released a video of Dunn being interrogated by police for more than an hour the day after Jordan Davis, 17, was shot to death in the backseat of an SUV at a Southside gas station. It happened November 23, 2012.

Dunn didn't dispute that he fired the shots, but he told police that he opened fire because he feared for his life.

"I was so afraid that I didn't have time to think. I only reacted," said Dunn.

Dressed casually and speaking calmly, Dunn answered questions from police and walked them through what he said lead up to him pulling out his 9 millimeter handgun and firing it eight times.

Dunn told police he had been at his son's wedding in Orange Park that day and was on his way to a hotel when he and his girlfriend stopped at a gas station to get a bottle of wine.

"There was an SUV next to us and then the music starts. I rolled down my window and I thought I was polite, and I asked them nicely, I didn't demand. I said, hey would you guys mind turning that down? They shut it off and I was like thank you."

Moments later Dunn told police the music was cranked up again. Then he says a passenger in the back seat of the SUV began threatening him.

"I saw a barrel come up on the window, like a single shot shotgun where there is a barrel. I didn't see this part of the barrel I saw that part of the barrel. It was either a barrel or a stick, but sir they're like we are going to kill you and then they said you are dead (expletive)," explained Dunn.

That's when Dunn said he reached into his glove box, pulled out his gun and fired four times from inside his car.

"Quicker than a flash I had a round chambered in it and I shot.," said Dunn.

Dunn said he then got out of his car and fired four more shots as the SUV was driving away.

"I'm at a loss to justify what I did on the second volley other than to say I thought they were going to be shooting back and I was keeping them from doing that," said Dunn.

Dunn said his girlfriend, who was inside the convenience store, came outside; she got in his car and then he drove them to a Jacksonville hotel without ever calling police.

A witness whose identity is concealed jotted down his license plate.

"No there was no shots shot back. I heard two loud bangs real quick and then the car was speeding off and I heard about another 4 or 5 after that and he had the gun in his hand."

Once at the hotel, Dunn, who said he was still scared, told police he ordered pizza.

"You call and order pizza. Why aren't you calling us?" asked a detective.

"I wanted to come back to my hometown to do that and our dog and everybody where they needed to be," said Dunn.

Dunn drove to his home in Brevard County the morning after the shooting and was arrested.

Police said Davis and his friends did not have any weapons.

Dunn is due in court Tuesday for a pretrial hearing.