America's refugee policy, up until now one of the least discussed elements of immigration reform, is coming into the spotlight as lawmakers grapple with the aftermath of the Boston marathon bombing. The two suspects in the case, Dzokhar Tsarnaev and Tamewrlan Tsarnaev, reportedly arrived in the United States as refugees when they were children, meaning there's little chance a background check at that point could have caught anything potentially threatening in their past.