Giffords and her husband founded the gun control group Americans for Responsible Solutions after the former congresswoman was shot in the head during a mass shooting during an event in Tucson, Ariz. in 2011. 

“Gabby and I are holding the victims of today’s massacre at the Washington Navy Yard in our thoughts and prayers, and we know that nothing will bring solace to the families who lost loved ones. As the hours and days pass, Americans should match their anger and sadness with gratitude for the sailors, Marines, civilians and first responders who are acting with courage today and support for the injured who have such a long road ahead. Gabby and I have been there. In times like this, it’s the ultimate affirmation to have a nation behind you.

Kelly is a retired NASA commander and Navy pilot. 

“And as proud members of the Navy family, we take note of the tragic fact that this terrible attack on men and women who dedicate themselves to keeping America safe did not occur in a war overseas — but in a mass shooting here at home.”

The group was a major player in the gun debate earlier this year, and ran ads urging tighter background checks for gun buyers in some members’ districts.