"We need another mother who is wiling to do what's right," Erica Smegielski says.
A short video introduces Erica Smegielski, whose mother, Dawn, was the principal of Sandy Hook Elementary and was killed while trying to protect her students.
Erica begins by saying, "I wish I were not here today ... I don't want to be here."
She says her mother was murdered.
People are openly weeping, the crowd is cheering and many are standing.
Murphy said, "And I am furious, furious, that in three years since Sandy Hook, three years of almost daily bloodshed in our cities, the Republican Congress has done absolutely nothing to prevent the next massacre. It stokes inside me a sense of outrage I’ve never felt before."
The crowd boos.
He leaves the stage to "enough is enough!"
U.S. Senator Chris Murphy of Connecticut has been a vocal gun-control advocate since 26 children and teachers were killed in 2012 at the Sandy Hook Elementary School in Connecticut.
Says he wishes he had not been there that "soul-crushing morning."