Darren Wilson has no intention of apologising to the family of Michael Brown, his lawyers have said.
Brown's parents expressed their anger after Wilson said he had a clean conscience and would change nothing about his actions on the day he killed their son in the St Louis suburb of Ferguson.
"He's a murderer," responded the 18-year-old's father, Michael snr.
James Towey, a member of the officer's legal team, told the Washington Post: "Even if [Wilson] gave the most heartfelt apology, they would still not like it."
"Taking a life is a horrible thing to have to do," said lawyer Neil Bruntrager. "And yet, the key phrase is, 'to have to do'. Because that is what he thinks. Is that going to make the Browns feel any less grief?"
Wilson learnt on Monday that he would not be charged over the killing, a ruling that triggered two nights of violent unrest in Ferguson.
Tensions eased over the Thanksgiving holiday but several demonstrators chanting "black lives matter" were arrested in New York for trying to disrupt the Macy's parade.
Despite criticism of the grand jury process, Missouri Governor Jay Nixon said he would not take up calls to bring in a special prosecutor.
Wilson, meanwhile, still faces a federal investigation into whether he violated Brown's civil rights.
The 28-year-old officer, whose new wife is pregnant with their first child, has been moving between safe houses since the shooting, his lawyers said.
He has rarely gone out in public, wearing disguises on occasional evening trips to the cinema.