The gun's design and intended use are at the heart of the plaintiffs' case, as the families' attorneys say the weapon should never have been sold to civilians.
A judge is considering whether a suit filed by family members of Sandy Hook Elementary School shooting victims can proceed. The plaintiffs argue that the rifle should not have been sold to civilians.
The companies had sought to dismiss the lawsuit filed by nine victims' families and a survivor over the AR-15 rifle used in the 2012 mass shooting at Sandy Hook Elementary School.
Obama cried after he remembered the children who were killed by a mass shooter in Newtown, Conn. "Every time I think about those kids, it makes me mad," he said.
The lawsuit filed on behalf of 10 victims claims that the Bushmaster AR-15 rifle never should have been sold to the public because it is a military weapon.
Sandy Hook and other mass killings have left people wondering how someone could engage in such behavior. Scientists say that genes can indeed predispose a person to mental illness or violence. But genetic variants alone can't explain why someone commits mass murder.