Fort Hood, Tex. ? Somberly reciting 13 names and 13 stories, President Barack Obama saluted the Americans killed at this Army post as heroes who died for their country — and promised a nation demanding answers that “the killer will be met with justice.”

Addressing a hushed crowd of thousands of soldiers Tuesday, the president spoke forcefully if indirectly of the alleged shooter’s motives in last week’s massacre, never mentioning Maj. Nidal Hasan by name.

“It may be hard to comprehend the twisted logic that led to this tragedy,” Obama said. “But this much we do know: No faith justifies these murderous and craven acts.”

It was an apparent reference to reports that Hasan had communicated with a radical Islamic imam. A vast investigation is under way, including questions about what the government knew about Hasan and whether action should have been taken.

The president’s remarks at a memorial service were personal, more about how the victims lived than how they died: the Eagle Scout, the newlywed, the expectant mother, the soldier eager to catch Osama bin Laden by herself. The president spent more time meeting privately with the wounded and with loved ones of those killed than speaking in public.

His tone stern, Obama pledged to the crowd that “the killer will be met with justice — in this world, and the next.”