Darren Wilson, the Missouri police officer who killed teenager Michael Brown in Ferguson, has stoked further anger after saying in an interview that he could not have done anything differently to have prevented Brown's death.

In his first public statements, which were broadcast by the ABC news channel on Tuesday, Wilson claimed his actions were justified because he feared for his life.

Wilson, who shot dead the 18-year-old a total of six times on August 9 according to autopsy reports also said he had a "clean conscience" and that he was "simply doing his job".

Al Jazeera's Daniel Lak, reporting from Ferguson, said that "community leaders were greatly disappointed by Wilson's lack of remorse".

The officer's latest statements came two days after a grand jury ruled that there was not enough probable cause to indict Wilson over Brown's death.

Bob McCulloch, the St Louis prosecutor who drew widespread criticism for his handling of the case, has cited "conflicting evidence" as the cause for the verdict.

On Monday, he issued a statement that analysts said showed he acted more as a defence attorney than his stated role as prosecutor.

Instead of expressing frustration over the grand jury's verdict, he blamed the media's portrayal of the case, saying "the 24-news cycle" was "the most significant challenge encountered in the investigation". 

'Special treatment'

Some US legal experts accuse McCulloch of being a key reason for why charges were not launched against the officer.

"There is no question that Darren Wilson got special treatment. He got a prosecutor who does did not request any particular charges be filed, a prosecutor who has close ties to where the defendant works," Lisa Bloom, a legal expert, told MSNBC.

She also blamed McCulloch for not being critical towards Wilson.

Wilson's court testimonies claim that the officer shot Brown twice during a struggle over his gun inside his car. Wilson said that following the shots, a wounded Brown ran away from the vehicle, before charging at the police officer again.

Wilson said he was forced to shoot Brown multiple times as he was running towards the officer.

But analysts have questioned how such a severely wounded and unarmed Brown could have been such a threat to Wilson that he had to shoot him in the head numerous times.

"Officer Wilson knows he is not armed. Even if a twice-shot bleeding Brown came running towards him again, why would he be threatened for his life?" Bloom said.

"Why would he have to shoot him in the head and kill him in that moment?"

Source: Al Jazeera and agencies