Mothers of the Movement to Speak at Democratic National Convention

The seven mothers have turned their grief into action.

The seven mothers sat down with "Good Morning America" co-anchor Robin Roberts in Philadelphia. They said Clinton is the candidate they believe can be held accountable to deal with gun violence and the use of excessive force by police in America.

"With the reform bill that she has in place, it implements it," said Maria Hamilton, the mother of Dontre Hamilton, who was killed by a Milwaukee police officer. "But we're going to hold her accountable for her actions with these bills and laws."

"She's the first presidential candidate that I'm aware of that has just said, 'This is a national crisis. It has to be dealt with,'" said Lucia McBath, whose son, Jordan Davis, was shot at a Florida gas station for playing music loudly. "Our communities and our families will never be safe unless we deal with gun violence in this country."

Fulton said she and the other women are committed to a movement that is "much bigger than us."

"It's something that has been placed inside us that says, 'Listen, you can't help your son or daughters, but you certainly can help other children,'" she said.

"I never thought that I would be in this position," said Carr. "I was thrown into it. I never wanted this. I'd rather have my son."

Reed-Veal, whose daughter was jailed after being pulled over in a traffic stop, spoke about where she finds her motivation.

"It hurts, and then you feel like you have to get up and fight, you know," she said. "We know there is nobody in the world of my family that believes that Sandy killed herself."

The women said the conversation around gun violence and excessive use of force by police is now a little louder because of the recent deaths of police officers in Dallas and Baton Rouge in the wake of nationwide protests over police brutality.

"This is a bad time to be a good cop in this country," said Reed-Veal. "OK? We need to remember they have lives too."

McSpadden said, "Everybody gets caught up on the uniform, but under that uniform is somebody who belongs to somebody who really loves them."

McBath described the current racial situation in the U.S. as a "bursting at the seams."

It's about "keeping guns out of the hands of the people who should not have guns," said McBath.