Central to Ms. Jordan’s defense is her accusation that her first husband and former business partner, Raymond A. Mirra, threatened to kill her or have her institutionalized. She has also said her second husband and Jude’s father, Emil Tzekov, a Bulgarian yoga instructor, sadistically abused the boy for years, causing a catatonic psychosis that doctors mistook for autism. Both men have vigorously denied the allegations.

Under direct questioning from her lawyer, Ms. Jordan began retracing the events that led her to conclude that she and her son were in grave danger. She recalled one night in December 2007, after a bath, when her son told her he was being sexually abused by his babysitter and Mr. Tzekov. Ms. Jordan said he was able to describe the abuse using a few simple words like yes, no and butt, as she asked him if any of the adults in his life were hurting him.

A month later, she said, Jude woke up one morning screaming, “Dad bad, dad bad.” That day, she asked Mr. Tzekov to move out of a house they were living in in Marin County, Calif.

A few months later, Ms. Jordan said Jude had learned to type messages on a computer. “Jude typed out, in some cases, very graphic descriptions the ways in which he was hurt both sexually and physically,” she said. “Most of it was about his father, but it was also about other people.”

She said Jude typed that his father had forced him to eat feces and had driven pins under his nails as a punishment, warning him not to talk. She said the boy also accused Mr. Mirra, his new wife and other people of being involved.

Ms. Jordan said she never reported the allegations to the police, but hired a San Francisco lawyer to investigate the matter and to contact the authorities. She also told her psychotherapist.