Spanish authorities suspected the CIA of involvement in the February 22 raid on the North Korean embassy in Madrid:
At least two of the 10 assailants who broke into the embassy and interrogated diplomatic staff have been identified and have connections to the US intelligence agency. The CIA has denied any involvement but [Spanish] government sources say their response was “unconvincing.”
The CIA countered the Spanish reports of its involvement by exposing its 'regime change' proxy group that executed the raid:
The group behind the late February operation is known as Cheollima Civil Defense, a secretive dissident organization committed to overthrowing the Kim dynasty, people familiar with the planning and execution of the mission told The Washington Post.
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“This group is the first known resistance movement against North Korea, which makes its activities very newsworthy,” said Sung-Yoon Lee, a North Korea expert at Tufts University.
Sung-Yoon Lee is "Kim Koo-Korea Foundation Professor of Korean Studies and assistant professor at the Fletcher School of Law and Diplomacy at Tufts University." He seems to believe that a violent raid by CIA related Korean-Americans on a North Korean embassy in a third country is "resistance".
The raid came a few days before the Trump-Kim summit in Hanoi. It was timed to blow up the negotiations.
In late March a Spanish judge named one Adrian Hong Chang as the leader of the embassy raid. Adrian Hong Chen is the head of the Cheollima Civil Defense/Free Joseon group. The judge demanded the extradition of Hong and his abettors from the United States. One of those persons has since been caught:
A U.S Marine veteran from Southern California was part of a group of dissidents wielding machetes and fake guns when they stormed North Korea's embassy in Madrid and tied up and beat officials inside, federal prosecutors alleged in a criminal complaint released Tuesday.
Spain is seeking to extradite Christopher Philip Ahn on charges including robbery, illegal restraint and criminal organization. Judge Jean Rosenbluth denied bond for Ahn during a Los Angeles court hearing attended by his wife, mother and about two dozen other supporters.
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Prosecutors said Ahn was arrested during a raid last week on the Los Angeles apartment of a co-defendant, Adrian Hong Chang, a leader of the Free Joseon group. Hong Chang was not at home and has not been arrested.
One reason that bail was denied is the extraordinary violence the group used:
The group — armed with machetes, iron bars, knives and fake guns — beat some of the workers and then tied them up with shackles and cables, prosecutors alleged. They put bags over some of the workers' heads, beat them and threatened them with the metal bars and guns, according to the court papers.
Interestingly it was Adrian Hong Chang, the group's leader, who ratted out Christopher Philip Ahn:
After the attack, Hong Chang also met with FBI agents at the bureau's office in Los Angeles and told them that Christopher Ahn, a former Marine, had participated in the attack.
One of the embassy workers later identified Ahn as an attacker from his LinkedIn profile picture.

Christopher Philip Ahn, Adrian Hong Chang
It seems that the Spanish authorities made enough of a stink to push the U.S. to seriously act against the group. But the embassy raiders still have their defenders.
At NKNews.org Professor Sung Yong Lee says that the prosecutor's court memo (pdf) in the Christopher Philip Ahn case is trash:
One expert told NK News they believed the U.S. government’s case, as reflected in the documents unsealed on Tuesday, had “more holes than a slice of Swiss cheese.”
“It shows the case was cobbled together in a rush when, after weeks of hedging, the DOJ, presumably upon orders from the White House and State, made the decision to quash Free Joseon,” Sung-Yoon Lee, an Assistant Professor at Tufts University’s Fletcher School, said.
“Sloppiness pervades the complaint,” he continued, pointing to what he said he was a number of inconsistencies in the account of the break-in.
“The criminal complaint is based entirely on implausible accounts by the DPRK staff, who had life-and-death incentives to claim having been overpowered by thugs,” he continued.
A statement carried on the website of Free Joseon last week, too, expressed “dismay” at the decision to arrest Ahn, saying the move derived from “criminal complaints filed by the North Korean regime.”
Earlier reporting from Spain contradicts the Professor's assertions. The case is not "based entirely on implausible accounts by the DPRK staff". It was the Spanish police who confirmed the violence of the perpetrators:
Police found the eight victims inside. They had been held hostage for two hours, had had bags placed over their heads, had been beaten and were scared. Two of them required medical attention.
The Free Joseon claim about "criminal complaints filed by the North Korean regime" is also false. The prosecution of a violent crime is mandatory under Spanish law. North Korea did not even file a complain:
The North Korean Embassy hasn’t pressed charges in Spain, and officials in Pyongyang haven’t officially commented on the attack.
Professor Sung-Yoon Lee isn't finished yet. In an Los Angeles Times op-ed he argues against extraditing Ahn to Spain. The headline follows his earlier argument:
Free Joseon is a North Korean resistance movement, not a criminal enterprise:
U.S. authorities have filed a criminal complaint alleging the dissidents used force and abused embassy staff during the Madrid action. Free Joseon denies the charges. For the U.S. to accept what is essentially a North Korean version of the events is to effectively defend the Kim regime. It sends the message to Pyongyang that its egregious crimes lie beyond the concern of the world’s presumptive champion of freedom and democracy.
The U.S. must not do Kim’s bidding. Our extradition treaty with Spain provides for a refusal to extradite if we regard the offense in question as political. The North Korean Embassy breach surely was that, and the U.S. should seek to protect the dissidents rather than hand them over to Spain.
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To stand up to tyranny in the name of freedom is not only not a crime, but also a right and duty. The United States should not quash this hallowed principle.
Christopher Ahn has U.S. citizenship. Adrian Hong has a Mexican passport. Neither is from North Korea. How can they be 'dissidents'? If North Korean citizens who want to regime change the United States would violently raid a U.S. embassy in a third country would that also be a "political" act committed by "dissidents"? The argument is obviously nonsense.
But to depict the criminals as "political", "resistance" and "dissidents" serves a purpose. This week Kim Jong-un visited Russia and met President Vladimir Putin. They talked about the nuclear negotiations. The Washington Post headlined:
Putin: Kim Jong Un needs international security guarantees to give up nuclear arsenal
Russian President Vladimir Putin emerged from his first summit with Kim Jong Un on Thursday saying that North Korea needs international security guarantees, not just U.S. pledges, to consider giving up its nuclear arsenal.
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“They [North Koreans] only need guarantees about their security. That’s it. All of us together need to think about this,” Putin told reporters after the talks with Kim.
Security guarantees make of course sense. Without them North Korea will not disarm at all. But the U.S. is not-agreement-capable, say the Washington Post authors:
North Korea has pushed for a declaration to formally end the Korean War, which ended in an armistice in 1953, without a peace treaty. Kim also has denounced past U.S.-South Korea military exercises as a provocation.
Trump called off some war games and dangled the possibility of an end-of-war declaration in the future, but direct U.S. pledges of support for the Kim regime’s hold on power are highly improbable, experts say.
“Nobody is in a position to give them the security guarantees they would like to have,” said Andrei Lankov, a North Korea expert at Kookmin University in Seoul. “They want a guarantee not only against an outside attack but also against possible internal discontent. . . . On balance, it’s a non-starter.”
Kim Jong-un would not demand guarantees against genuine internal discontent. North Korea's security forces surely know how to handle such. What he likely wants is that the U.S. re-commits itself to international law and refrains from interference in the internal affairs of his country.
The creation and manipulation of "resistance" movements, like the Free Joseon group, is a typical U.S. 'regime change' instrument. Such a "resistance" is then used as a pretext for violent regime change by military force. It was the expat 'Iraqi National Congress' of Ahmed Chalabi that played a large role in the build up to the war on Iraq. Similar "resistance" support was and is used to argue for war on Libya, on Syria and -coming soon- on Venezuela.
Professor Sung-Yoon Lee asks to recognize the embassy raiders as "political resistance". Free Joseon already declared itself to be the "government in exile" of North Korea. What happens when the U.S. recognizes it as such?
It seems that what the Professor is really aiming at is 'regime change' in North Korea, if necessary by U.S. force.
Sung-Yoon Lee's professorship is named after Kim Koo, "a leader of the Korean independence movement against the Japanese Empire, and a reunification activist after 1945". Kim Koo was fiercely opposed to U.S. plans to establish a separate government in South Korea. He was assassinated in 1949 by Lieutenant Ahn Doo-hee, an agent of the U.S. Counter-Intelligence Corps in Korea and member of a far right extremist group.
One seriously doubts that Kim Koo would have lend his support to the scheme that Professor Sung-Yoon Lee peddles under his name.
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Earlier Moon of Alabama pieces on the issue: