When South Korean officials boarded a stray North Korean fishing vessel in 2019, they were confronted with 16 corpses, two suspects and an acute political dilemma. Three years later, footage emerged of the two fishermen, who confessed to killing their fellow crew members, being handed over to the North Korean authorities and near-certain execution. The resulting controversy has pitted South Korea’s conservative administration against its left-leaning predecessor, raising doubts over South Korea’s respect for human rights, how Seoul handles relations with Pyongyang and a decades-old cycle of political revenge and recrimination.

“This case is an example of what happens when both the law and the facts are interpreted in a partisan way,” said Jeongmin Kim, lead analyst at Seoul-based information service Korea Pro. “It suggests that South Korean democracy is more dysfunctional than many people assume.”

On Tuesday, prosecutors conducted a series of raids on the homes of directors of South Korea’s National Intelligence Service, who served under left-leaning former president Moon Jae-in, over their handling of the fishermen’s repatriation. According to the South Korean constitution, all Koreans — whether from the North or South — are citizens of the Republic of Korea governed by Seoul. There is no extradition treaty between the two countries. Defenders of the Moon government, which was in office at the time of the incident, argued that the two fishermen were “heinous criminals”.

They added that the fishermen’s requests to defect to South Korea had been “insincere” and that the government’s decision to hand them over to Pyongyang after just three days of investigation was made in the interests of public safety. But critics have pointed out that the Moon administration was pursuing a policy of engagement with the North at the time of the arrests. They have cast the decision as a shameful and misguided capitulation to Pyongyang as well as an affront to the rule of law.