BOSTON -- The ex-wife of a German man on trial for charges of kidnapping his own daughter said she was "traumatized" and "devastated" when she found out that the 7-year-old girl had been whisked out of Boston during a supervised visit in 2008.

Christian Karl Gerhartsreiter, 48, is accused of kidnapping his daughter, Reigh, during a supervised visit in July 2008, injuring a social worker in the process, and fleeing to Baltimore, where he'd purchased a townhome.

Sandra Lynn Boss, 42, a senior partner in a London management consulting firm, testified Monday that she first met Gerhartsreiter whom she knew as Clark Rockefeller, at a party based on the board game "Clue" when she was still in business school.

"She found him to be intelligent -- in fact highly intelligent -- charismatic, witty and exceptionally persistent. He would not take no for an answer," Assistant District Attorney David Deakin said in his opening arguments.

Boss said in the spring of 1994, Gerhartsreiter proposed, and the couple married the following year in a Quaker ceremony on Nantucket. Boss said after they married, Gerhartsreiter's demeanor changed and he became more possessive and controlling.

Boss said Gerhartsreiter also started to complain that New York City had become too stressful, and suggested moving. Boss said they left New York in 1999, and moved into a rented "cute little vacation house" on Nantucket before moving to Vermont. A short time later, the couple bought a home in Cornish, N.H.

Boss said she separated from Gerhartsreiter and returned to New York in 2000, but when she realized she was pregnant, she decided to try to save her marriage.

Boss gave birth to the couple's daughter, Reigh, on May 24, 2001. Gerhartsreiter was not present for her birth. At first, the family hired nannies to care for Reigh when Boss returned to work, but eventually, Gerhartsreiter took over as primary caregiver.

Boss said a few years later, she decided to end the marriage and met with an attorney to begin divorce proceedings. When the divorce was finalized in 2008, Boss gave Gerhartsreiter an $800,000 settlement and agreed to three supervised visits a year with Reigh.

A few days before Christmas in 2007, Boss moved to England with her daughter.

In addition to the custody agreement's required social worker supervision, Boss hired a private investigator to keep tabs on her daughter and ex-husband during a July 2008 visit to Boston. But during that visit, Gerhartsreiter managed to flee the city with the girl.

"I was completely traumatized. I was hysterical. I was devastated. There is no way to describe it. It was horrible," Boss said.

At the time, Boss issued a video appeal for the return of her daughter, nicknamed "Snooks."

"I ask you now, please, please bring Snooks back. There has to be a better way for us to solve our differences than this way," Boss said in the recording.

Boss said she didn't hear anything from her daughter or ex-husband for six days. On Aug. 2, she said investigators told her they had located Reigh in Baltimore. Boss immediately flew to Washington, D.C., to be reunited with her daughter in Maryland.

Her ex-husband's lawyers claim that Gerhartsreiter was a distraught father who was insane when he took off with his daughter. Prosecutors are painting a picture of an odd con man who knew exactly what he was doing.

Boss said Gerhartsreiter told her that he was born and raised in New York City, and a childhood accident rendered him mute for a period of time. He also said he started attending Yale University when he was 14. Describing him as "one of the most intelligent people" she knew, Boss said she was not surprised that he said he was invited to enter Yale at 14 because she herself was offered to start college early, but declined.

Boss said Gerhartsreiter told her that his parents, George Rockefeller and Mary Roberts, were killed in a car crash when he was 18 while driving to visit him while he was away at school.

In contrast to what he told Boss, Gerhartsreiter was born to a middle class Bavarian family, came to the United States in the 1970s as a student and stayed with a family in Connecticut. He eventually moved to Wisconsin where he married a woman named Amy Jersild. He left her a day after the marriage, after obtaining a green card that allowed him to stay in the states, and moved to California where he assumed the name Christopher Chichester.

Gerhartsreiter lived there for a time with a San Marino couple who later disappeared, and human remains found in their former back yard several years later. California officials have tried to question Gerhartsreiter in connection with the case, but he has refused to talk with them.

He eventually surfaced in New York, where he said he worked on Wall Street, eventually wooing and winning Boss.