▶ Watch Video: Second suspect arrested in Sacramento mass shooting

Exactly one month after a shooting in downtown Sacramento left six people dead, officials announced murder charges for three suspected gunmen. Sacramento County District Attorney Anne Marie Schubert said charges were filed Tuesday against Smiley Martin, his brother Dandrae Martin and Mtula Payton, who has not yet been arrested.

All three suspects are charged with the murder of bystanders Johntaya Alexander, Melinda Davis and Yamile Martinez. All charges were enhanced with use of a handgun in the commission of crimes. All three suspects allegedly used 9mm handguns, and Smiley allegedly used an automatic 9mm handgun with a high-capacity magazine.

All three men, who are convicted felons, also face charges for illegally possessing firearms. Smiley Martin and Mtula Payton had previously been arrested several times, while Dandrae Martin had been arrested once before. 

Mtula Payton was out on bail on another case when the shooting took place, Schubert said. In a separate case, also filed Tuesday, he was charged with three counts of fraud.

The three suspects could face the death penalty if they are found guilty, but the decision to pursue capital punishment has not yet been made, Schubert said.

The investigation into the shooting is ongoing, and more charges could be brought in connection with the 12 people who were wounded in the shooting. Officials said there were over 100 shell casings recovered from the scene, and they believe the shooting was gang-related.

“This was a gun battle between two rival gangs,” Schubert said during a press conference. “The evidence shows the rival gang members armed themselves with weapons.”

The community shared over 200 tips, videos and photos, Sacramento Police Chief Kathy Lester said.

“This level of cooperation speaks to the character of those who came forward,” Lester said during the press conference. “It validates our work to earn the trust and the cooperation of our community as well.”

While police have arrested the Martin brothers, Payton remains at large.

The others who died in the shooting were identified as Sergio Harris, Devazia Turner and Joshua Hoye-Lucchesi. Turner has been identified as another gunman involved in the shooting, according to the Associated Press. Harris and Hoye-Lucchesi were also involved in the dispute with the Martins, Turner and Payton.