More arrests came Thursday in the investigation surrounding the shooting on Mother's Day, WDSU-TV reported.
A second suspect was arrested in the incident -- Shawn Scott, 24. Police said Shawn is the 24-year-old brother of Akein Scott, 19.
Police called Shawn a career criminal. He was also booked on 20 counts of attempted second-degree murder, police said.
According to police, the brothers are involved in the Frenchman-Derbigny Boys gang.
Akein Scott was arrested late Wednesday night at a home in eastern New Orleans. According to sheriff's records released Thursday, Akein was identified by a witness in a photo lineup.
Police also confirmed at a noon news conference that four others were arrested on charges of harboring Akein Scott and accessory after the fact.
The four people were identified as Justin Alexander, Bionca Hickerson, Nakia Youngblood and Brandy George.
"We all came back here, to make it clear that the culture of death and violence on the streets of New Orleans is unnatural," Mayor Mitch Landrieu said. "We will not let up. The rules of the game have changed on the streets of New Orleans."
The shooting injured 20 people, according to the arrest warrant released on Thursday. Originally, 19 people were reported injured in the gunfire that erupted during a second-line parade. Three people are still listed in critical condition.
Akein Scott appeared in magistrate court at 10 a.m. and smiled as the charges against him were read. His bond was set at $10 million.
"The people of New Orleans chose to be with us and not with the coward who fired into this crowd," NOPD Supt. Ronal Serpas said.