The people who were shot at are connected with the 30 Deep gang, the district attorney’s office said.
Moses and Williams were convicted on three counts of aggravated assault and weapons charges. A third man, Prentice McNeil, pleaded guilty and was sentenced to 10 years in prison.
McNeil, who also was one of the eight arrested in October 2007, already is in jail having been convicted of murder, aggravated assault and weapons charges for a shooting death that happened six days before the Mechanicsville incident.
The D.A.’s office said the majority of the members of those gangs have been arrested and prosecuted, and there has been no other signs of violence between them.
Moses and Williams will be sentenced at a later date.
--The Associated Press contributed to this article.