Connecticut's governor signed tough new gun ownership rules into law, four months after a gunman opened fire on an elementary school in the state, killing 20 children and six adults. The measure passed in the state assembly makes Connecticut the third state after New York and Colorado to tighten gun laws in the wake of the December 14 massacre at Sandy Hook Elementary School. More than 100 makes of rifles - including the Bushmaster AR-15 used by killer Adam Lanza in the Newtown school - were added to an existing, but now vastly expanded ban on military-style weapons. In addition, ammunition clips holding more than 10 rounds must now be registered, while new sales of the large clips are banned.