Police offered a $10,000 reward in the case, and investigators received several tips after images from the surveillance camera were released.
The video released Monday showed a crowd gathered for the parade suddenly scattering in all directions, with some falling to the ground. They appear to be running from a man in a white T-shirt and dark pants who turns and runs out of the picture.
As many as 400 people had come out for the event. Officers were interspersed with the marchers, which is routine for such events. The crime scene was about less than two miles from the heart of the city's French Quarter.
Two children were among those wounded.
The mass shooting showed again how far the city has to go to shake a persistent culture of violence that belies New Orleans' festive image.
Gun violence has flared at two other city celebrations this year. Five people were wounded in a drive-by shooting in January after a Martin Luther King Jr. Day parade, and four were wounded in a shooting after an argument in the French Quarter in the days leading up to Mardi Gras. Two teens were arrested in connection with the MLK Day shootings; three men were arrested and charged in the Mardi Gras shootings.