President Barack Obama said Sunday that the United States "can't accept" last week's killing of 12 people at Washington's Navy Yard as "inevitable," but the shooting should instead "lead to some sort of transformation" on gun violence in the United States. "It ought to be a shock to all of us, as a nation and as a people," Obama said at the Marine Barracks, just a few short blocks from the Navy Yard. "It ought to obsess us. It ought to lead to some sort of transformation." The president said during his speech that grieving with the families impacted by mass shootings is something he has had to do five times in his presidency, citing shootings in Fort Hood, Texas; Tucson, Arizona; Aurora, Colorado; Newtown, Connecticut; and now the Washington Navy Yard.

"Part of what wears on as well is the sense that this has happened before," Obama said. "What wears on us, what troubles us so deeply as we gather here today, is how this senseless violence that took place in the Navy Yard, echoes other recent tragedies."

The president continued: "Sometimes I fear there is a creeping resignation … that this is somehow the new normal. We can't accept this."