Some of the speakers denounced the "inexcusable and biased" news conference by District Attorney Andrew Womble, who announced that an investigation had found that law officers were justified in shooting the 42-year-old Brown and that no charges would be filed against them,
Some of those in attendance included the Rev. Dr. William Barber II, president and senior lecturer of Repairers of the Breach, the Rev. Dr. T. Anthony Spearman, president of the North Carolina Conference of the NAACP, and Keith Rivers, president of the Pasquotank County NAACP
WATCH: Full news conference by civil rights activists
The speakers announced that an amended letter will be sent to the US Department of Justice with demands to expedite an independent federal civil rights investigation of Brown Jr.'s death and open an immediate pattern-and-practice investigation into the sheriff's department and the district attorney's office.
The group also announced plans to take a delegation to Washington, D.C., to deliver the letter to US Attorney General Merrick Garland.
The three deputies who fired at Brown Jr. during a 44 second interaction as he tried to drive away April 22 when officers attempted to serve a drug search warrant returned to work earlier this week.
Pasquotank County Sheriff Tommy S. Wooten II said the three deputies will be disciplined and undergo training.
"This was a terrible and tragic outcome. And we could do better," Wooten said. "Every person in every job makes decisions. In law enforcement, we have a higher responsibility to do everything we can to make the best decision."