President Barack Obama has urged Americans to channel their anger about police shootings and race into a search for peaceful solutions. Obama spoke in Dallas, Texas at a memorial for five police officers. A gunman shot and killed the men as they were guarding a peaceful demonstration to protest police shootings of black Americans. Obama attended the memorial with Vice President Joe Biden and former President George W. Bush. It was the 11th time Obama has addressed a community after a mass shooting. Obama spoke about each of the five officers. He gave examples of their dedication and spoke of their final moments of duty. He praised them for risking their own lives to protect and serve the public. Nine other officers and two civilians were also wounded in the attack at the demonstration July 7. Hundreds of people had gathered to protest police killings earlier that week of black men in Louisiana and Minnesota.