Homicide detectives "are confident that Rockefeller is Christian Gerhartsreiter and the person named Christopher Chichester who was living in the Los Angeles area in 1985," Whitmore said.
Gerhartsreiter has been identified as a "person of interest" in the 1985 disappearances of Jonathan and Linda Sohus. Under the Chichester name, Gerhartsreiter rented a guesthouse at the couple's home in San Marino, a wealthy Los Angeles suburb.
Investigators were able to confirm Gerhartsreiter's identity after interviews with people who knew him in California in the 1980s, Whitmore said.
At the time of his Aug. 2 arrest in Baltimore, Gerhartsreiter had been living under the Rockefeller name. Police have said he snatched his daughter from a Boston street on July 27 in an elaborately planned kidnapping in which he hired two people to drive them to New York.
The district attorney's office and FBI in Boston said Monday they were not ready to declare that Rockefeller and Gerhartsreiter are the same person.
"One thing we are certain of: This defendant's true name is not Clark Rockefeller," said Jake Wark, a spokesman for the Suffolk prosecutor's office in Massachusetts.
Rockefeller's Boston attorney, Stephen Hrones, said for the first time at a news conference Monday that his client acknowledged using the name Christopher Chichester while living in California, and that he remembers the Sohuses but barely knew the couple and had nothing to do with their disappearance.
Skeletal remains were unearthed at the Sohus property in 1994 when new owners were putting in a swimming pool. Investigators at the time were unable to identify the bones but believed they probably belonged to Jonathan Sohus. Investigators have requested a new round of forensic tests, Whitmore said.
Two women who were friends with Christopher Chichester in the mid-1980s told the Los Angeles Times they noticed that much of the backyard at the Sohuses' home had been dug up around the time they disappeared. Chichester told them there had been plumbing problems.
Los Angeles County sheriff's investigators tried to question Gerhartsreiter in Boston last week, but he declined. No charges have ever been filed in the missing-people case.
Hrones said later in a telephone interview with The Associated Press his client told him he rented from the mother of one of the Sohuses.
"They just disappeared. He just noticed at some point that they weren't there any more. He didn't think much of of it, because he hardly knew them," Hrones said.
Hrones explained his client's decision to take a different name by saying he was an aspiring actor and "thought it was a more appropriate name."
"There is nothing wrong with using aliases as long as you don't use it to defraud," said the attorney, who said Rockefeller also remembers using the alias Christopher Crowe while he worked on Wall Street.
Hrones said his client remembers little of his past, believes his real name is Clark Rockefeller and has no memory of being Christian Gerhartsreiter. He said the man does speak a little German and understands the language.
Los Angeles County investigators' findings appear to support an account by Alexander Gerhartsreiter, who said he is the brother of the man being held in Boston.
Found at his home in Bergen, Germany, Alexander Gerhartsreiter told Boston Herald reporters that his brother was the son of an artist and homemaker in Upper Bavaria who felt he was better than his modest upbringing.
He said his older brother is 47 and was born in Siegsdorf, Germany, then raised until 1978 in the same house where his family lives today.
Alexander Gerhartsreiter said his brother moved to Connecticut as a student and never returned, initially keeping in contact but out of touch since he called his parents in 1985.
After Christian Gerhartsreiter moved to Connecticut, he married a young woman in Wisconsin in 1981 and left her after the wedding, the Boston Globe reported. The woman's sister told the newspaper that she believed the wedding was orchestrated so Gerhartsreiter could get a green card.
