What you need to know

Embattled former South Korean president Yoon Suk Yeol was found guilty of abuse of power, falsifying documents and obstruction of justice when he tried and failed to impose martial law in the country in 2024. He was also sentenced to five years in prison.

Yoon faces three other trials for charges ranging from insurrection to violating the campaign law.

The ruling comes more than a year after his brief rule throwing South Korea into political turmoilabandoned it deeply divided.

Here’s what to know about the important charges brought against Yoon.

On Friday, Yoon was found guilty of obstruction of justice by evading arrest; abuse of power by not calling a cabinet meeting before his declaration of martial law; and falsification of official documents.

Prosecutors accused him of using state institutions “for personal purposes” to hide flaws and undermine constitutional checks and balances.

In January last year, it took about 3,000 policemen, in two attempts, to finally take Yoon into custody for questioning on the insurrection case.

Yoon mobilized a large group of security officers who forming a human wall inside his residence to prevent arrest – a move that a special prosecutor investigating the case said was unprecedented.

Yoon, on the other hand, argued that the Corruption Investigation Office that tried to arrest him had no jurisdiction to investigate cases of insurrection.

The chaos surrounding the arrest, and the first failed attempt, “shows the flagrant violation of the law by Yoon, (his) conservative party, and South Korean security institutions”, said Mason Richey, an associate professor at Hankuk University of Foreign Studies in Seoul.

“The obstruction of justice trial is a way to ensure accountability for this,” he said.

Under South Korea’s constitution, sitting presidents are immune from criminal prosecution, except in cases of insurrection and treason.

Yoon was indicted on 26 January 2025. By then, the parliament had already voted to impeach him, but he had not yet been removed from office.

Prosecutors alleged that Yoon tried to subvert the constitution by declaring martial law in the absence of war or any national emergency.

In particular, he was accused of how he mobilized troops and police to seal the compound of the National Assembly to prevent lawmakers from obstructing his order, and how he ordered the arrest of the speaker of the National Assembly and then leaders of the main political parties.

Yoon initially claimed that he had declared martial law to protect the country from “anti-state” forces sympathetic to North Korea – but it soon became clear that he was encouraged by his own political troubles.

Prosecutors sought the death penalty, describing Yoon as “unrepentant”.

South Korea has not executed anyone since December 1997.

Former president Chun Doo-hwan, who ruled South Korea in the 1980s as a military dictator, was sentenced to death for leading a rebellion, although this was later commuted to life imprisonment. His ally and successor Roh Tae-woo was sentenced to a long prison term for his part in the insurrection. Both were eventually forgiven.

Prosecutors argued, however, that Yoon’s martial law trial in 2024 “damages the country’s dignity more severely” than the military coup carried out by Chun and Roh in 1979.

“We all saw how he disrespected the court, sniggering and laughing among his lawyers during witness testimonies. That didn’t help his case at all,” said law professor Lim Ji-bong.

Lim believes the judge will impose a life sentence, however, to “avoid making Yoon a martyr”. The death sentence carries a political risk because it will further alienate Yoon’s supporters and deepen the country’s chaos, he said.

US-based lawyer and Korea expert Christopher Jumin Lee believes Yoon will eventually be pardoned regardless of the sentence he receives, just like Chun and Roh.

“It’s a normal thing about Korean politics,” Lee said. “Whatever the sentence is, it’s a symbolic recognition of how serious the crime is.”

Prosecutors also alleged that Yoon tried to provoke North Korea into attacking the South to justify his declaration of martial law.

In laying this charge, the prosecution relied on evidence found by former military intelligence chief Yeo In-hyung with statements suggesting potential provocations. They also cited a memo that appeared to push for a move to “create an unstable situation or seize an emerging opportunity”.

This trial, which opened on Monday, will look into whether Yoon ordered drone flights in the North to provoke a military conflict between the Koreas, among others.

Yeo and Yoon’s former defense minister Kim Yong-hyun was also indicted on the same charge.

Yoon was also accused of perjury, as he testified during the trial of former prime minister Han Duck-soo last year on charges of aiding the insurrection.

Prosecutors alleged that Yoon lied and testified by claiming that he had long planned to hold a cabinet meeting before declaring martial law. Investigators said Yoon had no such plan and only called the meeting at Han’s urging.

Aside from the charges related to his martial law trial, Yoon was also charged with a series of charges.

He is one of 33 people charged for allegedly obstructing the investigation into the death of a young marine officer in 2023, and for helping the suspect in this case.

He is also accused of interfering in the 2022 presidential election and making false statements during his campaign.