Obama speaking at Navy Yard shooting memorial: 'Our tears are not enough ... We are going to have to change'

President Obama said that change to America's gun laws must come from public demand, because the political process alone isn't sufficient, speaking Sunday during a memorial service in Washington, D.C.

"Our tears are not enough," Obama said. "Our words are not enough. We are going to have to change."

Part of what wears on us is the sense that this has happened before, he said, noting the four previous mass shootings that he has found himself speaking about.

Gun control laws proposed after the Newtown shooting have been blocked in Congress, largely by Republican opposition.

Watch the president speak about the tragedy below.