WASHINGTON — The Justice Department is taking the final steps toward closing the politically charged investigation into the shooting death of an unarmed black teenager in Ferguson, Mo., and clearing the white police officer involved of civil rights charges.
Federal prosecutors have begun work on a legal memo recommending no civil rights charges against the officer, Darren Wilson, law enforcement officials said.
That would close the case in the death of 18-year-old Michael Brown. An investigation by the F.B.I., which is complete, found no evidence to support the charges against the officer, the officials said.
A broader civil rights investigation into allegations of discriminatory traffic stops and excessive force by the Ferguson Police Department remains open, however. That investigation could lead to significant changes at the department, which is overwhelmingly white despite serving a city that is mostly black.
The state authorities concluded their investigation into Mr. Brown’s death in November and similarly recommended no charges.
There is a high legal bar for bringing federal civil rights charges, and federal investigators had for months signaled that they were unlikely to do so. The Justice Department plans to release a report explaining its decision, though it is not clear when.
Attorney General Eric H. Holder Jr., has said that he plans to have it done before leaving office, probably in the next month or two if his successor is confirmed.
Three law enforcement officials discussed the details of the federal investigation on condition of anonymity because the report was incomplete and Mr. Holder and his top civil rights prosecutor, Vanita Gupta, had not formally made a decision. Dena Iverson, a Justice Department spokeswoman, declined to comment.
Benjamin L. Crump, a lawyer for Mr. Brown’s family, said he did not want to comment on the investigation until the Justice Department made an official announcement. “We’ve heard speculation on cases before that didn’t turn out to be true,” Mr. Crump said. “It’s too much to put the family through to respond to every rumor.” Mr. Crump said that at the end of last year that the Justice Department had told him that it was still investigating.
The lawyer for Mr. Wilson did not return calls for comment.
The shooting touched off protests that included violent clashes between demonstrators and heavily armed police. That incident, along with the death of Eric Garner — an unarmed black man who died after a chokehold by a New York police officer in July — sparked a nationwide discussion about policing, race and the use of deadly force.
President Obama, Mr. Holder and Mayor Bill de Blasio of New York, speaking about the issue in personal terms, said they understood the concern that minority neighborhoods had with the police. Those comments prompted rebukes from some law enforcement groups.
Mr. Holder said that the Justice Department’s investigation would be independent from the local authorities. While the F.B.I. and local officials conducted some interviews together and shared evidence, the analysis and decision-making were separate. Mr. Holder resisted calls from local officials to announce his conclusion alongside the county prosecutor last year, in part because he did not want it to appear as if they had reached their decisions together.
Federal investigators interviewed more than 200 people and analyzed cellphone audio and video, the law enforcement officials said. Officer Wilson’s gun, clothing and other evidence were analyzed at the F.B.I.’s laboratory in Quantico, Va. Though the local authorities and Mr. Brown’s family conducted autopsies, Mr. Holder ordered a separate autopsy, which was conducted by pathologists from the Armed Forces Medical Examiner’s office at Dover Air Force Base in Delaware, the officials said.
The federal investigation did not uncover any facts that differed significantly from the evidence made public by the authorities in Missouri late last year, the law enforcement officials said. To bring federal civil rights charges, the Justice Department would have needed to prove that Officer Wilson had intended to violate Mr. Brown’s rights when he had opened fire and that he had done so willfully — meaning he knew that it was wrong to fire, but did so anyway.
Soon after the shooting, witnesses told reporters that Mr. Brown had his hands up in a gesture of surrender when he was shot and killed by Mr. Wilson on a city street. The investigation, however, painted a murkier picture. Mr. Wilson told investigators that Mr. Brown tussled with him through the window of his police car and tried to grab his gun, an account supported by bruises and DNA evidence. Two shots were fired during that struggle.
What happened next as the confrontation moved into the street is in dispute. While some witnesses were adamant that Mr. Brown had his hands up, some recanted their stories. Mr. Wilson testified that Mr. Brown charged at him, and other witnesses backed up his account.
“I’m backpedaling pretty good because I know if he reaches me, he’ll kill me,” Mr. Wilson told a state grand jury, in testimony that investigators said was consistent with what he told the F.B.I. “And he had started to lean forward as he got that close, like he was going to just tackle me, just go right through me,” Mr. Wilson said.
The Ferguson investigation drew Mr. Holder into the spotlight on the issue of race, one he cares about deeply. He traveled to Ferguson, spoke of his experiences as a victim of racial profiling and emerged as a peacemaker during the tense days after the shooting, when police used tear gas on demonstrators and the National Guard was summoned.
The shooting also inflamed longstanding tensions between Ferguson’s black community and the police. Residents told investigators that the police used traffic citations in minority neighborhoods as a way to raise money for the city.
“These anecdotal accounts underscored the history of mistrust of law enforcement in Ferguson,” Mr. Holder said in September after returning from Ferguson, a suburb about 10 miles northwest of St. Louis.
It is not clear when the broader civil rights inquiry of the police department, known as a pattern or practice investigation, will be completed. Under Mr. Holder, prosecutors have opened more than 20 such investigations nationwide. The Justice Department recently called for sweeping changes to the Cleveland Police Department and negotiated an independent monitor to oversee the department in Albuquerque.
Mr. Wilson resigned from the department in November, citing threats of violence against him and other officers. “It is my hope that my resignation will allow the community to heal,” he said.
