Back in December of 2012, the entire nation watched on TV as Newtown Connecticut was the staging ground for a mass shooting, carried out by 20-year-old Adam Lanza. Connecticut Governor Dannel Malloy says the gunman used "an assault weapon to literally shoot his way into the building," before killing 26 students and teachers. Since that day, there have been several questions raised about what actually happened inside the Sandy Hook school that day. Today, we turn to a public school safety expert, Wolfgang Halbig, to find out what the school did right or wrong on that day. Mr. Halbig served as the Executive Director of the National Institute for School and Workplace Safety. He also served as a state trooper and US Customs Inspector in Miami. He's known all over the country for his safety and security expertise.