Moussaoui appeared to enjoy tapes of the 2001 terror attacks and even started singing a takeoff of Bruce Springsteen's "Born in the USA," changing "born" to "burn."
Former New York Mayor Rudy Giuliani described seeing people jump from the World Trade Center to escape the flames, one couple holding hands.
Jim Smith, a picture of his dead wife in a bloodied business suit on display, held back tears as he described how Moira Smith's death affected their daughter.
"The loss to Patricia, I can't begin to explain," CNN quoted him as testifying. "I tell her, her mom was a hero, and she died trying to save others."
The federal court jury, sitting in Virginia, is deciding whether Moussaoui, who testified he was supposed to be the 20th hijacker, should be put to death or sentenced to life in prison. Testimony resumes Monday.