Julianne Moore Launches Gun Safety Campaign: 'This Is My Responsibility As a Parent'

Like many parents, Oscar-winner Julianne Moore was deeply affected by the horrific shooting at Sandy Hook Elementary School in Newtown, Conn., in December 2012. "I remember my daughter [Liv, 12] came to work with me that day. I was doing a movie in Queens and when we got into the van, I actually said to the driver, 'Turn the radio off," Moore tells PEOPLE.