U.S. examines evidence in suspected chemical attack in Syria

The U.S. intelligence community is examining evidence related to the suspected chemical weapons attack in Syria over the weekend ahead of a possible military response. But CBS News' national security correspondent David Martin notes that "the last time that the U.S. struck Syria for the use of chemical weapons, U.S. intelligence had not come up with a smoking gun."

(Source: CBS News, https://www.youtube.com/watch?v=2qC5NHMHfPc)