A homeless man searching for cans was the first to see him—a full-term infant boy, umbilical cord attached, stuffed in a cardboard box inside a Dumpster. Police investigating how the baby wound up dead behind the 29th Street Cafe, a popular restaurant two blocks from the University of Southern California campus, soon had an answer: The baby's mother, third-year USC student Holly Ashcraft, 21, put him there.

That news was shocking enough to Ashcraft's classmates, seemingly none of whom knew that their sunny, outgoing friend was pregnant. But there was more. Initial tests showed that the baby was born alive, and police—who identified Ashcraft as the mother after following a tip from the homeless man—arrested her and charged her with murder. Then the Los Angeles Times reported that in 2004 Ashcraft had admitted disposing of a baby she said was stillborn (investigators found no body, and no charges were filed). "We're all floored by this," says USC junior Ashley Snodgrass, 20. "I saw Holly two weeks ago wearing jeans and a tank top, and I had no idea she was pregnant. She was just normal Holly."

Ashcraft, now in jail awaiting a Nov. 9 arraignment, was raised in Billings, Mont., and won a full scholarship to USC (her father, Terry, who has not spoken to her in three years, and mother Marlene are long separated). "She liked to go out and have fun," says her friend Melissa Barry, a USC junior. "She had a typical college dating life." Ashcraft lived alone in a room above the 29th Street Cafe, two blocks from a firehouse where, thanks to California's Safe Haven law, she could have dropped off her baby with no questions asked. While police have no word on the baby's father (Ashcraft has refused to answer any questions), her lawyer Paul Wallin says the full autopsy results, a few weeks away, will be crucial. "If the baby was not born alive," he says, "Holly did not commit a crime."

Still, her classmates wonder why Ashcraft chose to bear her burden alone. "She must have been so scared and in denial," says one friend. "I can't imagine her trying to kill anything."