Soon after Bryan's video leaked online, though, the GBI announced he was being investigated for possibly being something more than a witness.
GBI Director Vic Reynolds thanked the Arbery family for their patience at a press conference on Friday morning. "We know that we have a broken family and a broken community down in Brunswick", Holmes said.
A prosecutor said Mr Bryan had been "in hot pursuit" of Mr Arbery.
Ten weeks passed between Arbery's death and when the first arrests in the case were made.
Arbery was slain February 23 after a white father and son armed themselves and pursued him after spotting the 25-year-old black man running in their neighborhood.
The father and son were arrested on May 7, two months after the incident.
"Contrary to speculation, the polygraph examination confirms that on February 23 2020, the day of the shooting, William "Roddie" Bryan did not have any conversation with either Gregory or Travis McMichael prior to the shooting", said Gough.
Bryan filmed the encounter, but it took almost 10 weeks for the video to be made public. He and his father, a former Glynn County police officer, were not charged in the case for 74 days, until the GBI took over the case. It does not require intent to kill and carries an automatic life sentence. Authorities have not explained any circumstances of Bryan's suspected involvement.
Kevin Gough, an attorney for Bryan, maintained his client's innocence even when there weren't any charges against him.
The United States man who filmed mobile phone video footage of Ahmaud Arbery's fatal shooting in the state of Georgia was arrested Thursday and charged with murder in his death. "He is not a vigilante".
But the arrest warrant against Bryan accuses him of taking part in the chase and using his own vehicle with the "intention of confining and detaining Arbery".
"We called for his arrest from the very beginning of this process", the family's attorneys Merritt, Benjamin Crump, and L. Chris Stewart, said. "We want anyone who participated in the murder of Mr. Arbery to be held accountable".
Video of the shooting, captured by Bryan, surfaced on the Internet and led the case to gain national attention.
Memorial of Ahmaud Arbery at Echo Park in Los Angeles. Then a gunshot can be heard, followed by a second shot. Arbery was shot three times and collapsed in the street.
Carr also asked the Federal Bureau of Investigation to conduct a similar probe into the first two prosecutors' handling of the case. Because of those ties, Brunswick Judicial Circuit District Attorney Jackie Johnson recused herself from the case.