Story highlights Ferguson police Officer Darren Wilson tells ABC News that he is sorry about shooing

Officer who shot teen Michael Brown says he was simply doing his job

Wilson said Brown tried to take his gun and charged at him

in suburban St. Louis last summer. Ferguson, Missouri, police Officer Darren Wilson, in his first interview since he fatally shot unarmed teenager Michael Brown, said he's not tormented by that fateful encounter on a streetin suburban St. Louis last summer.

"I don't think it's haunting," Wilson told ABC News on Tuesday. "It's always going to be something that happened. The reason I have a clean conscience is that I know I did my job right."

Repeating what he told a grand jury investigating the shooting , Wilson said Brown reached into his police vehicle and grabbed for his gun. He feared for his life, he said.

It all started when Wilson asked the teenager to move out of the middle of the street, the officer told ABC's George Stephanopoulos. Brown walked over to his car and pushed the door back as Wilson tried to get out, the officer said.

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Photos: Unrest in Ferguson Photos: Unrest in Ferguson Police officers walk past the smoldering remains of a beauty supply store in Ferguson, Missouri, on Tuesday, November 25. Ferguson has been struggling to return to normal since Michael Brown, an unarmed black teenager, was killed by Darren Wilson, a white police officer, on August 9. The grand jury did not indict Wilson in the case, prompting new waves of protests in Ferguson and across the country. Hide Caption 1 of 34 Photos: Unrest in Ferguson A woman cleans up glass from a business' shattered window on November 25. Hide Caption 2 of 34 Photos: Unrest in Ferguson A Ferguson firefighter surveys rubble at a strip mall that was set on fire overnight. Hide Caption 3 of 34 Photos: Unrest in Ferguson Protesters run away after police deployed tear gas in Ferguson on Monday, November 24. Hide Caption 4 of 34 Photos: Unrest in Ferguson Police take position during clashes with protesters on November 24. Hide Caption 5 of 34 Photos: Unrest in Ferguson A protester stands in front of police vehicles with his hands up on November 24. Hide Caption 6 of 34 Photos: Unrest in Ferguson Police in riot gear move past a burning vehicle on November 24. Hide Caption 7 of 34 Photos: Unrest in Ferguson A looter in Ferguson walks out of a burning Walgreens on November 24. Hide Caption 8 of 34 Photos: Unrest in Ferguson Riot police clash with protesters on November 24. Hide Caption 9 of 34 Photos: Unrest in Ferguson Firefighters work on extinguishing a Little Caesars restaurant on November 24. Hide Caption 10 of 34 Photos: Unrest in Ferguson Smoke fills the streets of Ferguson as buildings burn on November 24. Hide Caption 11 of 34 Photos: Unrest in Ferguson Police officers grab a protester on November 24. Hide Caption 12 of 34 Photos: Unrest in Ferguson A woman treats her face for possible tear gas exposure on November 24. Hide Caption 13 of 34 Photos: Unrest in Ferguson People walk away from a burning storage facility on November 24. Hide Caption 14 of 34 Photos: Unrest in Ferguson A man steps out of a vandalized store on November 24. Hide Caption 15 of 34 Photos: Unrest in Ferguson A police officer runs by a burning police car on November 24. Hide Caption 16 of 34 Photos: Unrest in Ferguson Police officers stand guard as protesters confront them on November 24. Hide Caption 17 of 34 Photos: Unrest in Ferguson Protesters block streets in St. Louis after the announcement of the grand jury's decision on November 24. Ferguson is a suburb of St. Louis. Hide Caption 18 of 34 Photos: Unrest in Ferguson Police confront protesters in Ferguson on November 24. Hide Caption 19 of 34 Photos: Unrest in Ferguson A police officer points his rifle at demonstrators on November 24. Hide Caption 20 of 34 Photos: Unrest in Ferguson Protesters run for shelter as smoke fills the streets of Ferguson on November 24. Hide Caption 21 of 34 Photos: Unrest in Ferguson The glass windows of a store are shattered on November 24. Hide Caption 22 of 34 Photos: Unrest in Ferguson A demonstrator listens to a car radio as the grand jury's decision is delivered in front of the Ferguson Police Department. Hide Caption 23 of 34 Photos: Unrest in Ferguson Lesley McSpadden, mother of Michael Brown, is escorted away from the Ferguson Police Department on November 24. Hide Caption 24 of 34 Photos: Unrest in Ferguson A group of protesters vandalizes a police vehicle in Ferguson on November 24. Hide Caption 25 of 34 Photos: Unrest in Ferguson Police officers confront protesters on November 24. Hide Caption 26 of 34 Photos: Unrest in Ferguson Demonstrators block traffic during a protest in front of the Ferguson Police Department on November 24. Hide Caption 27 of 34 Photos: Unrest in Ferguson Demonstrators gather outside the police station on November 24. Hide Caption 28 of 34 Photos: Unrest in Ferguson Protesters gather as they wait for the announcement of the grand jury decision on November 24. Hide Caption 29 of 34 Photos: Unrest in Ferguson Members of the media line up in a parking lot across from the Buzz Westfall Justice Center on November 24. Hide Caption 30 of 34 Photos: Unrest in Ferguson Residents begin to gather at the Michael Brown memorial ahead of the grand jury announcement. Hide Caption 31 of 34 Photos: Unrest in Ferguson National Guard troops arrive ahead of the grand jury announcement. Hide Caption 32 of 34 Photos: Unrest in Ferguson Members of the Missouri National Guard are escorted out of the Buzz Westfall Justice Center. Hide Caption 33 of 34 Photos: Unrest in Ferguson Demonstrators are confronted by police as they block a street before the grand jury announcement. Hide Caption 34 of 34

"As I looked back at him, punches started flying," Wilson said in the interview, which aired Tuesday night. "He threw the first one and hit me in the left side of my face."

Wilson doesn't know how many times he got hit.

"I just know there was a barrage of swinging and grabbing and pulling for about 10 seconds," Wilson told ABC. "I reached out my window with my right hand to grab on to his forearm."

Wilson said he wanted to move Brown away.

"I just felt the immense power that he had. And then the way I've described it is, it was like a 5-year-old holding onto Hulk Hogan. That's just how big this man was," Wilson said. "He was very large, very powerful man."

Wilson is 6-foot-4 and 210 pounds; Brown was the same height and weighed nearly 300 pounds.

Brown unleashed another punch and struck the officer in his face, Wilson said.

"How do I survive," Wilson recalled thinking. "I didn't know if I'd be able to survive another hit like that."

Wilson reached for his gun and told Brown to back off or he would shoot, the officer said.

"You're too much of a (word bleeped) to shoot me," Wilson said Brown told him, before grabbing the top of the officer's gun.

Wilson tried to squeeze off two shots but the gun jammed twice.

Brown, he said, tried to reach the trigger guard to shoot Wilson. Wilson got a shot off on his third attempt, he said.

"He gets even angrier," Wilson said. "His aggression, his face, the intensity just increases. He comes back in at me again."

There was another shot, Wilson told ABC. The officer gets out of his car and goes after Brown, who turns around from 30 to 40 feet away.

Wilson said Brown reached into his waistband with one hand and made a fist with the other.

"He starts charging me," Wilson said in the interview. "My initial thought was, is there a weapon in there."

Wilson said Brown never had his hands up as if to surrender.

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Photos: Officer Darren Wilson Photos: Officer Darren Wilson Officer Darren Wilson – Officials released never-before-seen photos of Ferguson, Missouri, police officer Darren Wilson after it was announced Monday, November 24, that a grand jury had chosen not to indict Wilson for the shooting death of Michael Brown. These photos were taken on the day of Wilson's altercation with Brown, and they were released as part of the evidence that was presented to the grand jury. Read what Wilson told the grand jury Hide Caption 1 of 7 Photos: Officer Darren Wilson Officer Darren Wilson – Another photo taken on the day of Wilson's altercation with Brown. Hide Caption 2 of 7 Photos: Officer Darren Wilson Officer Darren Wilson – Another photo taken on the day of Wilson's altercation with Brown. Hide Caption 3 of 7 Photos: Officer Darren Wilson Officer Darren Wilson – Another photo taken on the day of Wilson's altercation with Brown. Hide Caption 4 of 7 Photos: Officer Darren Wilson Officer Darren Wilson – Another photo taken on the day of Wilson's altercation with Brown. Hide Caption 5 of 7 Photos: Officer Darren Wilson Officer Darren Wilson – Another photo taken on the day of Wilson's altercation with Brown. Hide Caption 6 of 7 Photos: Officer Darren Wilson Officer Darren Wilson – Another photo taken on the day of Wilson's altercation with Brown. Hide Caption 7 of 7

Brown charged at Wilson, the officer said.

"I decide to shoot," he said "I fired a series of shots and paused. I noticed at least one of them hit him. I don't know where. I saw his body kind of flinch a little."

Wilson said he paused again and commanded Brown to stop.

Brown kept coming. Wilson said he fired again and Brown flinched as if hit.

With Brown just 15 feet away, Wilson said, he backpedaled. Brown got closer and positioned himself to tackle the officer, according to Wilson, who then shot the teenager in the top of the head.

Wilson told ABC that he was sorry for the loss of life but that he was simply doing his job and following his training.

"We just want to have a normal life," he told ABC. "That's it."

The death of Brown sparked violent demonstrations in the days after the shooting and again on Monday night, when it was announced that a Missouri grand jury would not charge Wilson. There were more protests Tuesday, in Ferguson and around the nation

In the hourlong interview, Wilson said he could not have done anything differently.

Asked if the incident would have turned out differently if Michael Brown had been white, Wilson said no.

Wilson, 28, spent six years with the Ferguson police department before being placed on administrative leave following the shooting. Wilson worked for two years at another police department before that.

He remains on leave, pending the outcome of an internal investigation, Ferguson Mayor James Knowles told reporters Tuesday.

"No decision has been made," Knowles said. "His current employment status has not changed."

Last week, people close to the talks told CNN that the officer was in the final stages of negotiations with city officials to resign from the police department.

Wilson has told associates he would resign as a way to help ease pressure and protect his fellow officers.

The United States Justice Department is also investigating whether Wilson violated Brown's civil rights.

In newly released transcripts of testimony that the grand jury heard while considering whether to bring charges in Brown's death, Wilson told the jurors that he had never fired his gun on duty before that day.

Wilson told the grand jury his original goal was to arrest Brown, after identifying him as a possible suspect in a shop theft.

Wilson fired 12 shots, according to the grand jury proceedings.

The officer told the St. Louis County grand jury that two shots were fired during a struggle at his police vehicle and that he then fired three bursts of gunfire as he chased and later backed away from Brown. He testified that his Sig Sauer .40-caliber gun held a maximum of 13 bullets.