A senior official from the naval brig in Charleston, SC, testified on Tuesday in federal court here that he had twice observed Mr. Padilla weeping in the electronically monitored cell where the military detained him for three years and eight months. The brig's technical director, Sanford E. Seymour, also said that Mr. Padilla, an American citizen who was designated an enemy combatant in 2002, sometimes slept on a steel bunk without a mattress, that the windows in his 80-square-foot cell were blackened and that brig employees covered up their nametags around him.