Cosmo Setepenra Photos: Pictures of Baton Rouge Gunman Gavin Long

The gunman who killed three police officers and wounded three others in a shooting Sunday morning in Baton Rouge, Louisiana, has been identified as Gavin Eugene Long, MSNBC reports. Long went by the name Cosmo Setepenra online. He discussed the Dallas attack on police officers and recent police shootings of black men in social media posts. "Violence is not THE answer (its a answer), but at what point do you stand up so that your people dont become the Native Americans...EXTINCT?," he wrote on Twitter on July 13. Long, described as a 29-year-old black male from Kansas City, Missouri, was killed at the scene of the shooting, CBS News reports. His birthday was Sunday. Long was a former Marine, who was honorably discharged in 2011. Click through the gallery to see more photos of Long. (Twitter)