Former Connecticut school construction official Konstantinos “Kosta” Diamantis fled to Greece ahead of his sentencing on federal bribery charges earlier this month.
Now the FBI says it’s looking for him, and the U.S. Marshals Service says it knows where he is.
If authorities do take Diamantis into custody, will Greece extradite him back to the United States?
The answer, as with most issues where lawyers get involved: It depends.
Legal experts contacted by CT Insider said there are two main issues that could complicate any attempts by the United States to extradite Diamantis from Greece. The first are his allegations, contained in a 10-page missive to his attorney and obtained by CT Insider and other news outlets, that his prosecution was politically motivated. The second – and more weighty, experts said – is his dual Greek-U.S. citizenship.
“In this case, the strongest potential issue appears to be citizenship,” Georgios Fouskarinis, a Greek criminal defense and extradition attorney, wrote in an email from the capital, Athens. “If Diamantis is legally regarded as having been a Greek citizen when the relevant offences were committed, Greek law could prohibit his extradition.”
Then there’s the politics wild card. Extradition is half legal process, half diplomatic negotiation, experts said. Diamantis and his attorney, Norm Pattis, have applied for a pardon from President Donald Trump. Depending on how federal officials view his case, they could either pressure Greece to hand him over or decide to take the opposite tack.
“Another thing that may make the case unique is the possible diplomatic pressure on Greece,” Fouskarinis said.
Who is Diamantis, and what is extradition?
In October 2025, a federal jury in Bridgeport found Diamantis guilty on 21 counts of bribery, extortion, conspiracy and making false statements to investigators after a nine-day trial and 10 hours of deliberation. The charges stemmed from Diamantis’ time overseeing state school construction contracts.
Diamantis didn’t show up at a sentencing hearing earlier this month. He later spoke to CT Insider from Greece, claiming – as he did in his email to Pattis – that he was prosecuted for opposing some of Gov. Ned Lamont’s Covid-19 policies, among other reasons.
“The governor didn’t like my bravado and I’m being outspoken,” Diamantis said in a recent interview. “I guess I wasn’t from Yale, I don’t know.”
Now federal officials are looking for Diamantis. If caught, he could face extradition.
Extradition is the legal process of transferring someone from one jurisdiction to a different jurisdiction where they face criminal charges or conviction – whether that’s between states or between countries. In this case, it would be transfer from Greece to the United States.
The extradition process between countries is generally governed by a treaty. The United States and Greece have had such a treaty since 1931.
Diamantis made three requests to travel to Greece before his trial. In opposing those motions – which a judge ultimately rejected – Assistant U.S. Attorney Jonathan N. Francis said Greece was “a troubling destination country” because of two provisions in its extradition treaty.
“The extradition treaty between the United States and Greece does not require either country to extradite (i) its own citizens, or (ii) defendants charged with an ‘offense of a political character,’ which could include the public corruption crimes with which Diamantis is charged,” Francis said.
But what do those mean, and how big of a problem are they?
Saying the prosecution was political may not help
Experts who spoke with CT Insider agreed that while the provision about offenses “of a political character” could complicate or delay Diamantis’ extradition, it is probably his weakest argument.
Fouskarinis said Greek courts take a narrow view of what counts as a political crime – “a crime against the state or the constitutional order,” as he explained it.
“Bribery or public-corruption offenses would not ordinarily become political offenses simply because they involve a politician or public official,” Fouskarinis said.
Mitchell Epner, a former federal prosecutor now at the firm Kudman Trachten Aloe Posner LLP, agreed.
“That’s talking about if somebody contends that they are a revolutionary or that they are a member of an opposition party, and what they have been convicted of are political crimes – that is, crimes of a nature where they’re trying to change the government,” he said. “That’s not what’s going on here.”
There is a “recognized ground of objection” for prosecution of non-political crimes that are, nonetheless, politically motivated. But Fouskarinis said this, too, would be an uphill battle for Diamantis, as it “requires evidence going beyond the political context of the case itself.”
This is where diplomacy comes in, according to Ken White, a former federal prosecutor and founding partner at the Los Angeles firm Brown White & Osborn LLP. White said if a country wants to refuse an extradition request, it’s often likely to choose grounds for that refusal that are less “politically sticky.”
“Usually, in this kind of situation, for diplomatic reasons, foreign countries prefer to go with the easier reason than the harder reason,” he said. “If it’s true that they can refuse to extradite their own citizens, they’re more likely to use that as an excuse than concluding that it’s political persecution.”
With citizenship, timing is important
Diamantis surrendered his U.S. passport as a condition of his release. However, he later obtained a Greek passport, which prosecutors said they believe he used to flee.
But the real question, according to Fouskarinis, isn’t when Diamantis obtained a Greek passport – it’s when he became a Greek citizen.
If Diamantis became a Greek citizen after he committed the crimes for which a jury found him guilty, then it’s unlikely that citizenship would block his extradition, Fouskarinis said. However, if he were a citizen from birth – even if he formally certified that citizenship after he committed the crimes – that could trigger the provision in the treaty about not extraditing citizens.
“His citizenship file and the legal basis on which Greece recognized his nationality would therefore be extremely important,” Fouskarinis said.
There’s strong evidence Diamantis could be in luck here. In that July 2024 court filing opposing Diamantis’ pre-trial request to travel to Greece, Francis, the federal prosecutor wrote that since Diamantis’ parents were Greek citizens, he had “the constitutional right in Greece to
claim citizenship as of the time of his birth.”
Even on the questions of citizenship, however, both Fouskarinis and White also acknowledged that political or diplomatic pressure could play a role. Indeed, as White pointed out, extradition has both diplomatic and legal elements, and parts of the process run through the U.S. State Department.
“Countries don’t always exercise the right not to extradite people,” White said, speaking in general terms. “It’s a matter of how palatable he is.”
There are also practical considerations. Extradition hearings can drag on for months or, in some unique cases, even years, experts said. Prosecutors acknowledged as much in that July 2024 court filing, saying they believe extradition would be possible through Greece’s membership in the European Union, but “that process potentially involves multiple proceedings and levels of review, and could take years.”
While those proceedings dragged on, a person facing extradition would generally be held in jail by the country they fled to, according to Epner.
“In some places, the nature of that jail is so awful that the person waives extradition to get out of that country’s jail and start fighting the case from the U.S.,” he said, pointing to a high-profile case – former crypto currency executive Sam Bankman-Fried, who abruptly waived extradition after being held at a jail in the Bahamas with reportedly rough conditions.
On the other hand, White said if the court won’t extradite Diamantis and he’s free within that country, “certainly there are worse things than living in Greece.” Such a situation would severely limit Diamantis’ ability to travel abroad or ever return to the United States, White said – something he expressed a deep desire to do in a recent CT Insider interview. But Diamantis did not take staying in Greece off the table.
Ultimately, Fouskarinis emphasized that Greece could well decline to extradite Diamantis.
“In this case, the strongest potential issue appears to be citizenship,” he said.
Diamantis is now scheduled to be sentenced – whether he shows or not – on Wednesday.
This article originally published at Kosta Diamantis fled CT to Greece. His citizenship status could complicate extradition.
