BOSTON -- Former colleagues of a Cambridge couple accused of acting as Russian spies said Tuesday they were shocked to hear about the charges.

Donald Howard Heathfield and Tracey Lee Ann Foley, of Cambridge, were among 10 people arrested by federal authorities and accused of carrying out long-term, deep-cover assignments in the United States on behalf of Russia.

"(My) jaw hit the ground," said David Bookbinder, who once worked with Heathfield at Global Partners eight years ago. He said the charges against Heathfield, who federal officials say took the identity of a dead man, seem surreal.

"Now that I know, you know, hindsight, The realm of possibility is there. He was kind of standoffish, aloof," he said.

Craig Sandler, president of the Statehouse News Service, went to graduate school with Heathfield at the Harvard Kennedy School of Government. As classmates, he said they had many discussions about global issues.

"He was quite inspiring, interesting. He did project a lot of confidence that people could solve the world's problems," said Sandler. "The way that he would express his ambitions for his work and the content of his work, sure, were pretty ambiguous and mysterious."

Sandler said Heathfield is "what I would want in a spy, but so are a lot of people."

Heathfield and Foley were arrested at their recently purchased condominium at 35 Trowbridge Street. (Read Mortgage Records) They have lived in the Massachusetts city for the past 11 years.

They appeared briefly in federal court in Boston Monday and were held without bail.

Foley's real estate associates at the Red Fin firm in Somerville said she was hired in February and interviewed by at least two people at the time. In a blog posted on the company's Web site, the company said she "interviewed well."

"As with every agent we hire, Red Fin validated her Social Security number, her deal history and that her real estate license was in good standing; as with every agent we hire, we ran a criminal background check, which came up clean," the company said in the blog.

The company said Foley was "well-liked," and in customer surveys she was described as "friendly and helpful."

The couple is charged with conspiring from the 1990s to the present to work as spies for a foreign government, and court papers referred to them as the "Boston conspirators."

There was no clue in initial court papers how successful the couple might have been, but deep-cover agents are the hardest spies to detect because they blend in as Americans with no obvious connection to a foreign government, officials say.

Court papers say the alleged spies had one mission, to "Americanize ... gather information about the U.S. for Russia ... recruit sources who are in, or able to infiltrate, U.S. policy-making circles."

Members of the group allegedly encrypted data in images and used invisible ink in order to conceal their activities, also communicating with Moscow by radiograms. Documents say the team of alleged spies was seeking nuclear weaponry information.

In 2004, federal officials allege, Heathfield met with an employee of the U.S. government with regard to nuclear weapons research, specifically small-yield, high-penetration warheads recently authorized by Congress. In October 2004, the couple allegedly discussed ways they could send secret messages to Moscow.

Heathfield and Foley were leading the most American of lives. Heathfield was identified as a Harvard graduate and was the CEO of Future Map, a business based at his home in Cambridge, according to its website. He incorporated the company in February, according to records from the Massachusetts Secretary of State.

"Future Map helps organizations learn to anticipate change and be a step ahead of competitors," the website says. The company also claims to have offices in Paris and Singapore.

The wife of a business associate of Heathfield said she could not believe the charges. "Holy crap," was her reaction when informed by NewsCenter 5.

"Nothing I've ever seen Donald do connected him to Russia," said Charles Kellogg, who worked with Heathfield at Global Partners in Boston. Kellogg said while working for Global, an international consulting firm, Heathfield traveled often to the Middle East.

The FBI affidavit released Monday indicates that both Heathfield and Foley were using names that were not their own and had been under federal investigation for almost a decade.

In 2001, the FBI searched a safe deposit box at a Cambridge bank and found film negatives of the woman calling herself Foley that had been developed by a Russian film company.

Heathfield, the affidavit claims, had the birth certificate, and had taken the identity of a man who had died in Canada in June 2005. Court documents allege that Foley also falsified her identity and travel documents.

Property records at the Middlesex County Registry of Deeds show that the couple purchased the Trowbridge Street condominium for $790,000 earlier this month.

The family's Cambridge neighbors said they are also shocked by the allegations.

"I'm very surprised. I hope for their sake they're not, but if they are, they're in the wrong country then," said Montse Monne-Corbero.

Monne-Corbero said Foley and Heathfield appeared to be normal neighbors, saying they shoveled snow and had teenage sons who occasionally got loud when they had friends over.

"The woman was pretty, short blonde hair -- very friendly. But we never socialized. Him, I didn't see as much," she said.

Monne-Corbero said she thought the family moved out last week after buying a house. She said the family lived at the Cambridge address for two to three years.

Foley, who is a licensed real estate agent, gave a $50 campaign contribution to State Rep. Marty Walz in 2004.

Walz said Heathfield was in her class at Harvard's Kennedy School of Government and said she sent out an e-mail asking for campaign contributions from her classmates and Foley must have signed the check.

On her real estate website, Foley said she is a native of Montreal who lived and was educated in Switzerland, Canada and France.

"Ann's cultural awareness and international experience make her sensitive to the needs of other people. She strives for excellence in everything she does. Ann succeeds through her ability to ensure quality service, honesty and integrity," the website says.

Russian diplomats were scheduled to meet with U.S. authorities to discuss the case on Tuesday. Russia's foreign minister said his country is waiting for an explanation on the arrests.