The FBI is investigating the shooting of Ahmaud Arbery, a black jogger, by two white men as a possible hate crime, the Arbery family’s attorney said Monday, claiming that federal authorities had launched a criminal inquiry into two district attorneys and the police department involved in the case. Lee Martin, who represents the family of Arbery, 25, whose 23 February killing in Brunswick, Georgia, was captured on a graphic video recording that sparked national outrage, said he met with officials from the Department of Justice last Thursday. Martin said they told him federal investigators were looking into potential “criminal and civil” violations by two officials who later recused themselves from the case. They are George Barnhill of the Waycross judicial district, who recommended no arrests, and Jackie Johnson of Glynn county, who has denied accusations she ordered police to make no arrests on the day the unarmed Arbery was shot. The Georgia chapter of the National Association for the Advancement of Colored People (NAACP) has called on both Barnhill and Johnson to resign and face charges of obstruction of justice. Martin said the FBI was also looking into the actions of the Glynn county police department. The suspects Gregory McMichael, 64, and his son Travis, 34, were finally arrested by the Georgia bureau of investigation (GBI) and charged with Arbery’s murder on 8 May, three days after the video received national publicity, and 74 days after the shooting. The case took a further step forward last Thursday, when the GBI arrested the man who recorded the video, William Bryan Jr, and charged him with felony murder. “This is a vast conspiracy at this point,” Martin said in a four-and-a-half-minute video posted on Monday on TMZ. “They’re spreading the net here. They said the GBI doesn’t anticipate making any additional arrests, but the FBI very well may.” Martin has been highly critical of the pace of the investigation into the shooting. He said he was told a further part of the FBI probe was whether the actions of anybody involved in the case breached Arbery’s rights of equal protection under the US constitution and civil rights law. “All citizens are entitled to the same protection under the law,” he said. “This case makes it clear that all black citizens in south Georgia aren’t getting the same protection because if you shoot anybody in the street in broad daylight, just in general you expect at least an arrest. There were no arrests made.” Neither the Department of Justice nor the US attorney’s office for the southern district of Georgia responded to the Guardian’s request for comment on Monday, a federal holiday. But in an 11 May statement, a DOJ representative, Kerri Kupec, confirmed investigators were assessing evidence “to determine if federal hate crime charges are appropriate”. Gregory McMichael, a former law enforcement officer, told detectives he suspected Arbery of burglary, and that Arbery had attacked his son before being shot. Police initially treated the shooting as a case of self-defense and allowed the McMichaels to go free, despite the video of the shooting suggesting a different story.