From there, police say, Rockefeller and Reigh were dropped by an unwitting livery driver -- who since has cooperated with police -- at a Boston hospital where 30-year-old Aileen Ang, an acquaintance of Rockefeller's he met at a Boston sailing club, picked up the father and daughter and drove them to New York City.
Rockefeller's arrest may shed light on his mysterious past. "Nobody knows who this guy is," a high-ranking Boston police official assigned to the task force in charge of investigating Rockefeller's background told ABC News earlier this week. "He is a ghost."
Boston police said investigators have not located a valid Social Security number for Rockefeller. They have also found no wedding certificate documenting his marriage to Sandra Boss, the mother of the missing child who got custody of the little girl after their 2007 divorce, the official said.
The task force has not found any work history for Rockefeller, who told one former neighbor in New Hampshire that he was a "physicist" and fashioned himself as a "philanthropist" who sat on the boards of various nonprofits.
Investigators also are unclear about Rockefeller's education history, the official said, despite reports that he commonly told acquaintances he attended Yale and Harvard. Some people have told authorities that Rockefeller said that his parents died in a car crash when he was young; others were told he was homeschooled as a kid.
The Boston Police Department last placed Rockefeller at Grand Central Terminal in New York City. He had told Ang that he was heading for a boat he had recently purchased, a 72-foot catamaran called Serenity.
Rockefeller, who has been connected to several aliases, is not a descendant of John D. Rockefeller, the wealthy New York industrialist, but he apparently did not dissuade other people from assuming they may be related.
When the Rev. Brian Marsh of Trinity Church in Cornish, N.H., where Rockefeller and Boss attended church until about two years ago, asked about Rockefeller's famous last name, he said Rockefeller didn't answer him directly.
Instead, he took out a pocketknife with the name "Nelson Rockefeller" on it, Marsh said. "He implied a connection."
Other neighbors in Cornish, a former artist's colony where Rockefeller and his wife Sandra purchased a historic property, described the kidnapping suspect as "elusive" and "vague" about personal details. They said he was a doting dad, but described him as paranoid, noting that he built a mote around the property and set up a security perimeter.
Rockefeller, known for his preppy attire, also allegedly boasted an extensive art collection that he said included several original works by Mark Rothko.
Rockefeller and Boss, who reportedly married in the early 1990s on the Massachusetts island of Nantucket, divorced in 2007. A judge impounded the divorce case file at the couple's request.
Boss, an executive level consultant who attended Harvard Business School, was awarded custody of their daughter and changed the child's name from Reigh Rockefeller to Reigh Boss.
Rockefeller was allowed supervised visits with his daughter. On Sunday afternoon, when the alleged kidnapping took place, the child and her mother were in Boston from their current home in London so that Rockefeller could see his daughter.