The Department of Justice announced on Wednesday that after a six-month inquiry it has concluded no civil rights charges should be brought against Wilson for killing Michael Brown. A grand jury in St Louis decided last November not to indict Wilson on state charges.
"There is no evidence upon which prosecutors can rely to disprove Wilson's stated subjective belief that he feared for his safety," the Department of Justice report concluded, according to law enforcement officials.
The decision concludes the second half of a politically-charged investigation into Wilson's shooting of Brown on 9 August following an altercation in a residential side-street.
An attorney for Wilson said the Justice Department's decision amounted to an "exoneration" of the former Ferguson officer. "Obviously the reaction is one of relief," Neil Bruntrager told CBS. "It's been a long road for him. Now he needs to get on with his life."
It was widely expected by protesters who allege that Brown's killing was a criminal act.
"Michael Brown's death, though a tragedy, did not involve prosecutable conduct on the part of officer Wilson," US attorney general Eric Holder said at a press conference in Washington.
Holder reminded those disappointed by the inquiry's conclusion that he had promised during a visit to Ferguson "not that we would arrive at particular outcome, but that we would pursue the facts, wherever they might lead".
Comment: The facts? The federal government rarely if ever traffics in the facts. The grand jury investigation alone was an exercise in ignoring facts and choosing data that fit the narrative of a dangerous black man threatening the life of a scared police officer:
- Ferguson: Darren Wilson's pathetic testimony sounded like the spewings of a paranoid white supremacist
- Ferguson grand juror sues prosecutor to speak out
- Grand juror sues prosecutor of Michael Brown case, alleges mishandling of case
- "Witness 40": Fraud exposed in Ferguson
- Ya think?! Ferguson prosecutor says witnesses lied under oath to grand jury
- Unorthodox police procedures come to light in grand jury documents
Describing the federal inquiry as "both fair and rigorous from the start", he said its conclusions were "supported by the facts we have found".
"I urge you to read this report in full," Holder said.
In a statement issued by their attorneys, Brown's parents said they were "saddened by this decision", adding that it meant "that the killer of our son wouldn't be held accountable for his actions".
Prosecutors might have charged Wilson under a 19th-century federal law - known technically as Section 242 of Title 18 - that makes it a crime for anyone acting with government authority to "wilfully deprive a person of a right or privilege protected by the Constitution or laws of the United States."
Evidence that Wilson intentionally victimised Brown because of his race would have been needed for civil rights officials at the Justice Department to prosecute the 28-year-old officer, who quit his job at the Ferguson police department following the state grand jury's decision.
The same high bar was in place for a two-year investigation into the 2012 killing in Florida of Trayvon Martin, an unarmed black teenager, by George Zimmerman, a neighbourhood watchman. The Justice Department said last month thatZimmerman would not be charged.
Wilson's supporters accused Eric Holder, the attorney general, of burying news that no charges would be brought on the same day his officials accused Ferguson police of a pattern of racial bias in a sweepingly critical report after a review of the department's practices.
"The FBI appeared to conclude their inquiries into officer Wilson months ago," said Ron Hosko, the president of the law enforcement legal defense fund. "Yet the Attorney General seems to have delayed the announcement of this decision despite knowing the conclusions."
Protests erupted on the streets of Ferguson, a small northern suburb of St Louis, after Brown's death in August. For successive nights, heavily armed police clashed with demonstrators, firing teargas and rubber bullets to drive hundreds of people out of the centre of the town. A night of rioting, looting and arson followed November's grand jury decision.
An attorney for Brown's family was expected to comment later on Wednesday. Wilson's attorney could not be reached for comment.
it will not end well for anyone. This decision will further polarized the population of much of America, like gasoline on a fire.