She knew him as Clark Rockefeller, a casual friend she met while they both took sailing lessons. They went to a couple of boat shows together, had lunch, and he introduced her to his 7-year-old daughter, Reigh.

Aileen Ang didn't think much of it when he asked her if she would drive him to New York so he could go see his new boat, a 72-foot catamaran named Serenity. But on July 27, Ang became his unwitting getaway driver when he allegedly snatched his daughter during a supervised visit in Boston.

Rockefeller, whose real name is Christian Karl Gerhartsreiter, is charged with kidnapping his daughter after losing custody of the girl in a divorce. Their disappearance set off an international manhunt. They were found in Baltimore six days later. The girl was unharmed and now lives in London with her mother.

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Testifying at his kidnapping trial Friday, Ang said she had no idea he had abducted his daughter.

"He said he'd purchased the boat and he wanted to go look at it," Ang said.

He asked her to pick him up at the Boston Sailing Center, where the two had first met the summer before. He arrived minutes later with his daughter, nicknamed "Snooks."

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

Ang said Gerhartsreiter spent part of the ride lying on the back seat with his daughter, explaining that the girl had a headache and they both wanted to take a nap.

During the ride, he insisted that she not use her cell phone, saying that it made him nervous, she said. Twice when she picked it up to make calls, it had been shut off, she said.

He also refused her repeated requests that they stop to use the bathroom and get gasoline.

"He said he was getting nervous that he'd miss his boat launch and that he was getting antsy," Ang said.

When they arrived at Grand Central Station in New York City, he got out of the car with his daughter.

"I said, 'Well, have a nice trip,' and he just slammed the door," Ang said.

She said her cell phone rang almost immediately. A friend was calling her to tell her that an Amber Alert had been issued for the girl. Ang said she called police and was questioned by the FBI for 12 hours.

Prosecutors say Gerhartsreiter, 48, is a German-born con man who has been changing his identity and fabricating elaborate stories about himself since moving to the United States as a teenager in 1978.

His lawyers say he is mentally ill with a delusional disorder that makes him not guilty of a crime. They say he had a "psychotic break" when he lost custody of his daughter to his ex-wife, Sandra Boss, in December 2007.

Liza Brooks, a Brookline psychologist who provided therapy for Reigh Boss during her parents' divorce and also worked to coordinate her father's supervised visits, testified Friday that she found the man she knew as Clark Rockefeller "weird."

Prosecutors said Gerhartsreiter refused to provide proof of his identity during his divorce and ultimately agreed to accept a settlement of $800,000 from his wife and to have three supervised visits a year with his daughter.

Brooks said he canceled his first scheduled visit with her in the spring of 2007, saying he was too busy with construction contracts and travel. Brooks said that as they discussed the second scheduled visit in July, she asked him what he would say if his daughter asked him why he hadn't had any contact with her in six months.

"He said he would say, 'sorry,"' Brooks said.

She said he also told her he had another family, something authorities have said is another fabrication.

In a status letter on the case she wrote in September 2007, Brooks said she was concerned that Gerhartsreiter "appears fairly willing to give up lots, including his daughter, in exchange for monies," an apparent reference to the divorce settlement.

Defense attorney Tim Bradl, in questioning Brooks, repeatedly suggested that his client's lack of contact with his daughter and his willingness to give up custody of her for money was "probably not rational for a father to do, right?"

But Brooks said she did not have an opinion on whether it was rational behavior.

Also testifying Friday was Julie Gochar, a Baltimore real estate agent who said she sold Gerhartsreiter a $450,000 carriage house on July 18, nine days before he allegedly kidnapped his daughter.

Gochar said he had contacted her months earlier, identifying himself as a ship's captain from Chile who wanted to move to Baltimore with his daughter.

Gochar said she called the FBI after recognizing photos of him in news reports about the Amber Alert. He was arrested on Aug. 2 near the home.