The ex-wife of the man who calls himself Clark Rockefeller was back on the witness stand Tuesday for cross-examination by his lawyers, after providing damning testimony against him a day earlier.

Sandra Boss was answering questions for the defense in her former husband's high-profile kidnapping trial.

Boss testified Monday that Rockefeller, whose real name is Christian Karl Gerhartsreiter, wooed her in the 1990s with his intellect and charisma but became controlling shortly after they got married.

Boss, who referred to her ex-husband as "the defendant," said that at first she had no reason to doubt his accounts of his past but slowly became increasingly suspicious of his stories during their 12-year marriage.

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• Partial List of Witnesses at the 'Clark Rockefeller' Trial

She said she was "completely traumatized" when he took their then 7-year-old daughter last July.

Concerned for her daughter's safety, she asked a judge to grant her full custody in their 2007 divorce. Her husband agreed, but in exchange asked for a large divorce settlement.

As part of the $800,000 settlement, he agreed to have just three supervised visits a year with his daughter, Reigh, she said. But during their first visit, in July 2008, Boss' worst fears were realized: Her ex-husband took the girl and fled.

Gerhartsreiter is accused of kidnapping their daughter after shoving a social worker who was overseeing the visit to the ground. Father and daughter were found in Baltimore six days later. The girl was unharmed.

Prosecutors say Gerhartsreiter, a German-born man, is a con artist who has used numerous aliases since moving to the United States in 1978.

The defense claims Gerhartsreiter is mentally ill.

Boss' testimony was the first time she told her story in public. She remained composed throughout much of her testimony, her voice trembling slightly when she talked about her daughter, nicknamed Snooks.

Boss said that she met the man she knew as Clark Rockefeller in New York in 1993 through her sister, first seeing him at a "Clue" board game-themed party he held. He came as Professor Plum, she as Miss Scarlet.

He was "very intelligent, very polite, could talk about anything," she said. "I mean, really interesting ... also, really very charming."

They started dating when she was in Boston attending Harvard Business School and he was living in New York. He proposed in the spring of 1994, and they got married in a small ceremony on Nantucket in October 1995.

She said she saw an angrier side of him after they were married in 1995, as he became more controlling and critical of her friends. Eventually it became a "stressful" relationship, she said.

The couple first separated for several months in 2000, but Boss said she decided to stay and work on her marriage after learning she was pregnant.

She was working as an executive at a management consulting company in New York City, and he was not contributing any income to the household, she said. After several moves, the family ended up in Cornish, N.H., then in Boston in 2006.

In early 2007, Boss finally filed for divorce. She said she had grown suspicious of her husband's stories about his past and hired a private detective.

"I was asking him to find out who my soon-to-be ex-husband was," she said.

After getting a report from the investigator, she filed an affidavit in probate court asking for full custody of their daughter.

"The point of it was that the defendant was not the person he'd said he was and that was a cause for great concern," she said.

Boss said her husband filed a response in court, but did not provide proof of his identity.

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