After the tragic shooting at Sandy Hook Elementary School, calls for gun-control legislation have begun. Sen. Dianne Feinstein (D-Calif.) said on NBC's Meet the Press that she plans to introduce a bill to ban assault weapons. Even West Virginia Democratic Sen. Joe Manchin, who calls himself a gun supporter, says he sees no reason for these types of weapons. But as Congress considers new laws, the scientific research we need to craft the best policies is in short... (GunPolicy.org)