Only a true nutcase (read: NRA) would argue that the Second Amendment to the United States Constitution protects the thugs who snuff out innocent children.
For the record, the amendment reads:
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.Those who use their guns to kill innocents do not a militia make; nor does securing a free state dictate the murder of that state's children.