Ms. Bremmer, who writes mystery books and whose family raises and trains dogs, said she took comfort in her sense that Brandenn must have chosen his course because his organs -- heart, liver and kidneys -- were needed by ailing people.

"He was so in touch with the spiritual world," Ms. Bremmer said. "He was always that way, and we believe he could hear people's needs. He left to save those people."

The vital organs were donated the night he died, as he had long made clear was his wish, she said.

Ms. Bremmer said that she and Mr. Bremmer had always known that Brandenn, who had two much older sisters, was unusual. The day he was born, doctors struggled to find a pulse, she said.

"Things were different right from then," she recalled. "It's almost like my baby died, and an angel took his place."

Still, many who knew him said he seemed quite ordinary, despite the circumstances of his life that might have led, or even been expected to lead, to eccentricity or worse.

He could act like an adult one moment and like a child the next, said Jim Schiefelbein, former principal of University of Nebraska-Lincoln Independent Study High School, which Brandenn started attending at age 6 and finished four years later. Mr. Schiefelbein recalled how at his graduation, Brandenn, then 10, offered a few words of thanks, spoke to the news media and promptly began running around the room with other children at the ceremony.

At Colorado State in Fort Collins, where he took college courses before transferring to a community college in Nebraska closer to home, two professors who knew him described him as reserved, but not withdrawn -- clearly set apart in a sea of 18-to-22-year-olds, but not entirely isolated.