[UPDATE2] Obama urges stop to gun violence after Zimmerman verdict SANFORD, Fla., July 14 (UPI) -- U.S. President Obama said Sunday Americans should "respect the call for calm reflection" from Trayvon Martin's parents after the acquittal of George Zimmerman. The slain teen's parents used social media to thank supporters following Saturday's not guilty verdict in the Florida murder trial of Zimmerman. Martin's family did not address the acquittal of their son's killer in a brief series of Twitter messages; however, supporters in California and Washington took to the streets overnight to express their disagreement with the verdict. In a statement issued by the White House, Obama urged Americans to respect the justice system. The death of Trayvon Martin was a tragedy. Not just for his family, or for any one community, but for America. I know this case has elicited strong passions. And in the wake of the verdict, I know those passions may be running even higher," he said. But we are a nation of laws, and a jury has spoken. I now ask every American to respect the call for calm reflection from two parents who lost their young son. And as we do, we should ask ourselves if we're doing all we can to widen the circle of compassion and understanding in our own communities. We should ask ourselves if we're doing all we can to stem the tide of gun violence that claims too many lives across this country on a daily basis. We should ask ourselves, as individuals and as a society, how we can prevent future tragedies like this. As citizens, that's a job for all of us. That's the way to honor Trayvon Martin. Martin's family was not present the acquittal verdict was handed down by the six-woman jury deciding the fate of Zimmerman, who was charged with second-degree murder for killing the unarmed 17-year-old in a gated community in Sanford, Fla., on Feb. 26, 2012, the Orlando Sentinel reported. Sybrina Fulton, Trayvon's mother, thanked supporters later: "Lord during my darkest hour I lean on you. In San Francisco and Oakland, Calif., residents took to the streets to vent their frustrations with the verdict. The protest began about midnight in areas known for an active nightlife, but caused minimal disruptions to traffic, the Post said.