For weeks after Ahmaud Arbery was killed while running down a road in coastal southern Georgia, there were few public developments in the case of a 25-year-old unarmed black man who was shot while being pursued by two white men with weapons in February.
Then a graphic video of the shooting surfaced online, spurring widespread outrage.
Within days, the Georgia Bureau of Investigation had taken over the case. The video was criticized by celebrities and politicians alike, including President Trump, who called the footage “very, very disturbing,” and former Vice President Joseph R. Biden Jr., the presumptive Democratic presidential nominee, who said Mr. Arbery had essentially been “lynched before our very eyes.”
And in a major turn, the authorities announced on Thursday night that they had arrested two suspects in the case and charged them with murder and aggravated assault.
The video — which by Friday officials had described as “a very important piece” of evidence in moving forward with criminal charges — was first posted by WGIG, a local radio station in Brunswick, Ga., which said it had obtained the footage from an anonymous source.
But in a twist emblematic of the small-town politics that have defined the case, that source turned out to be a criminal defense lawyer in town who had informally consulted with the suspects.
The lawyer, Alan Tucker, said in an interview on Friday that the video had come from the cellphone of a man who had filmed the episode and that he later gave the footage to the radio station. Mr. Tucker’s role was confirmed by Scott Ryfun, who oversees the station’s programming.
Asked why he had leaked the video, Mr. Tucker said he had wanted to dispel rumors that he said had fueled tension in the community. “It wasn’t two men with a Confederate flag in the back of a truck going down the road and shooting a jogger in the back,” Mr. Tucker said.
“It got the truth out there as to what you could see,” he added. “My purpose was not to exonerate them or convict them.”
The video, taken from inside a vehicle, shows Mr. Arbery running when he comes upon a white truck, with one man standing next to its open driver’s-side door and another in the bed of the pickup. Mr. Arbery runs around the truck and disappears briefly from view. Then the man standing outside the truck tussles with him, and three gunshots are heard.
The authorities identified Travis McMichael, 34, as the suspect who shot Mr. Arbery. His father, Gregory McMichael, 64, a retired investigator at the local district attorney’s office, was also charged.
Before the charges were filed this week, two prosecutors had recused themselves from handling the case, citing professional ties to Gregory McMichael. Mr. Tucker, too, said he had been an acquaintance of Mr. McMichael’s from their work in legal circles.
Reports suggest Mr. Tucker had consulted with the McMichael family in some capacity during the investigation, though it is not clear to what extent. Reached by The Washington Post before his arrest on Thursday, Gregory McMichael referred questions to Mr. Tucker.
Mr. Tucker declined to comment on his conversations with the McMichaels on Friday, citing attorney-client privilege.
“I’m not going to tell you what I told them or what they told me,” he said, using profanity to say that any conversations — had they occurred, he said — were none of the public’s business.
At times during the interview, a woman could be heard in the background whispering suggested answers to Mr. Tucker.
By Friday afternoon, Mr. Tucker said that it had been decided that he would not be retained as the lawyer for either of the McMichaels, and it was unclear who was representing them.
Mr. Tucker said he would not be representing anyone else involved in the case, as the authorities announced on Friday that they were pursuing a number of leads, including investigating the man who took the video.
The man, Roddie Bryan, lives in the neighborhood. He had shared the video with the police before sharing it with Mr. Tucker and was cooperating with the authorities, his lawyer, Kevin Gough, said in an interview Friday evening.
“Mr. Bryan has never tried to hide anything from anybody,” Mr. Gough said. “If anybody wanted a copy of the video, he would give it to them.”
But he said the added attention, including the scrutiny from the authorities, had come as a shock to his client, a mechanic who had since lost his job and received threats. “The atmosphere down here is very volatile,” Mr. Gough said. “People are in fear. That’s all a result of the last few days.”
The latest developments in the case on Friday fell on Mr. Arbery’s birthday, when he would have turned 26. Thousands of people commemorated the occasion by running 2.23 miles, a nod to Feb. 23, the date he was killed.