Connecticut Sen. Chris Murphy spoke with Boston Public Radio on Friday about his new book that examines what he says is the American failure to address gun violence. Murphy was elected to the U.S. Senate a month before the shooting at Sandy Hook Elementary School in 2012, when 20 children between the ages of 6 and 7, and six adults, were shot dead by Adam Lanza.

"This easy access to weapons of mass destruction is probably the simplest and most accurate explanation of the mass shooting epidemic," Murphy said. "Would Adam Lanza have ever come up with this disgusting, perverse courage to walk into that school if he didn't have an AR-15?"

Gun violence affects everyone, even those who haven't gone through a traumatic experience, Murphy noted. "This issue is one that no one can avoid any longer, because every parent now has to listen to their child coming home and talking about an active shooter drill," he said. "Now every parent has to confront the threat of violence."

Murphy's latest book is The Violence Inside Us: A Brief History of an Ongoing American Tragedy.