New details in the Clark Rockefeller case seem to confirm some of the other names police suspect he has used.

A German man who lives in a small mountain town called Bergen positively identified photographs of Rockefeller and a man known as Christopher Chichester as his long-lost older brother, Christian Karl Gerhartsreiter, who left home at age 17.

Alexander Gerhartsreiter, 34, who was only 5 or 6 when his brother left home, said the man told the family in his last phone call to them in 1985 that he had changed his name to Christopher Chichester because Americans were unable to pronounce his birth name.

"It seems you found my brother," Alexander, who was only 5 or 6 when his brother left home, said to the Boston Herald from his home in Upper Bavaria, Germany. "It really is a shock. That is definitely him. ... This is quite heavy."

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Rockefeller's attorney, Stephen Hrones, had an hourlong jailhouse meeting with his client Friday afternoon and said Rockefeller speaks German but only remembers "bits and pieces" of his childhood, according to The Boston Globe.

Rockefeller, 48, who is in a Boston jail, is accused of parental kidnapping for allegedly snatching his 7-year-old daughter, Reigh "Snooks" Storrow Mills Boss, from a city street on July 27 during a supervised visit.

He was caught in Baltimore with the child, allegedly using another assumed name, Charles "Chip" Smith, and had purchased a home and boat in an apparent attempt to start a new life. About $12,000 in cash and 300 1-ounce gold coins also were found in his apartment after his arrest, police said.

Christopher Chichester has been wanted for questioning in the 1985 disappearance and presumed murder of Jonathan and Linda Sohus, a San Marino, Calif., couple from whom he rented a carriage house.

In 1994, bones believed to be those of John Sohus were found in three separate bags on the property when the residents were installing a swimming pool. But police have never been able to positively identify the skeleton as belonging to the missing man, and the remains of his wife have never been found.

Shortly after the newlywed couple vanished, their tenant Chichester did, too.

Detectives allege Rockefeller is a con artist who has for decades been traveling across the United States, concocting stories and using multiple aliases to live a lavish life.

Authorities have not confirmed that Christian Gerhartsreiter, Christopher Chichester and Clark Rockefeller are the same person. Gerhartsreiter was a German exchange student who lived with at least two Connecticut families when he came to the United States.

But the Suffolk District Attorney's Office in Massachusetts estimates that Rockefeller has at least a dozen different aliases. Another they're investigating is Christopher Crowe, the name of a Connecticut man who tried to sell a pickup truck belonging to John Sohus after he disappeared.

Rockefeller's attorney said his client's memory is spotty. He recalls, for instance, a Scottish nanny and a family road trip to Mount Rushmore in a station wagon, Hrones said.

"He has no memory of being from Germany or of having a German brother," his lawyer told the Globe on Friday. "He tells me he's Clark Rockefeller. I believe him. I haven't been shown any hard evidence that he's something other than what he tells me he is."

Hrones said his client has no recollection of coming to the United States in the late '70s and living in Berlin, Conn., as an exchange student, according to the Globe. He also doesn't remember marrying a Wisconsin woman named Amy Jersild in 1981 at the very young age of 19, only to leave her a day after their wedding, according to marriage papers.

Rockefeller doesn't recall being a tenant of John and Linda Sohus, though he remembers living in California. And though he has memories of working on New York's Wall Street as a stockbroker, he doesn't know what name he used or where and when he had the job.

"He tells me he still doesn't remember about the past. He remembers bits and pieces, silly sorts of things," Hrones told the Globe. "He doesn't remember murdering anybody ... and he doesn't remember being a tenant of the couple that were murdered."

Germany's BKA, the equivalent of the FBI, told FOX it has no criminal record associated with anyone by the name of Christian Gerhartsreiter.

U.S. law enforcement officials have enlisted the help of German authorities to figure out Rockefeller's identity, the Foreign Ministry in Berlin confirmed to the Globe.

"We are now checking if he could be the German citizen Christian Karl Gerhartsreiter," a spokeswoman told the paper during an interview in German.

Police in Boston and Los Angeles say they have no record of Rockefeller before 1993, which is about when his foggy memories become clearer. He remembers marrying Reigh's mother, Sandra Boss, in 1995. The couple divorced in December, in large part because she grew suspicious about his past.

Childhood friends have described Gerhartsreiter as a mischievous, restless loner, the Globe and the Herald reported.

Alexander and Christian Gerhartsreiter's ailing mother, 78-year-old Irmengard Gerhartsreiter, told the Herald that she didn't know the man in the pictures of Rockefeller and Chichester.

But her younger son recognized him right away.

Alexander said the older brother he barely knew was born in Siegsdorf, Germany, in 1961, left home as a teenager to move to Connecticut as a student and then cut ties with the family about 20 years ago, around the time the Sohus couple disappeared.

Germany and his hometown in the Alps were "too small" for Christian, who had his sights set on bigger and better things, his brother told the Herald.

"He wants always to be in a big world," Alexander said.

When the Herald reporter informed him of the Clark Rockefeller alias, Alexander wasn't surprised.

"Sounds like my brother."

Click here to read more on this story from the Boston Herald.

Click here to read more on this story from The Boston Globe.

Click here to read more on this story from The Los Angeles Times.

Click here to read more on this story from MyFOXBoston.com.

FOX News' Catherine Donaldson-Evans, Greg Palkot and The Associated Press contributed to this report.