Open: This is Face the Nation, April 21

The latest on the Boston bombings: Gov. Deval Patrick, D-Mass., Boston Police Commissioner Ed Davis, CBS News' John Miller and Bob Orr, Sen. Tom Coburn, R-Okla., Rep. Mike McCaul, R-Texas, former New York City Mayor Rudy Giuliani, and former Secretary of Homeland Security Tom Ridge. Plus a conversation on gun control with Newtown family members Neil Heslin, Carlee Soto and Erica Lafferty.