South Korea's Yoon is in court for a hearing in his criminal trial

South Korean President Yoon Suk Yeol is in court for a hearing where his lawyers are contesting his arrest on a criminal charge alleging he was orchestrating a rebellion when he imposed martial law

South Korean President Yoon Suk Yeol appeared in court Thursday for a hearing where his lawyers contested his arrest on a criminal charge alleging he was orchestrating a rebellion when he briefly imposed martial law in December.

Security was heightened as the motorcade transporting Yoon arrived at the Seoul Central District Court and dozens of his supporters rallied nearby.

The preliminary hearing will involve discussions of witnesses and other preparations for his criminal trial, and the court was also to review the request by Yoon’s lawyers to cancel his arrest and release him from custody. Such challenges are rarely successful.

Yoon was indicted Jan. 26 on the rebellion charge carrying a potential punishment of death or life in prison. In South Korea, presidents have immunity from most criminal prosecutions, but not on charges of rebellion or treason.

The indictment alleges his imposition of martial law was an illegal attempt to shut down the National Assembly and arrest politicians and election authorities. The conservative Yoon has said his martial law declaration was intended as a temporary warning to the liberal opposition and that he had always planned to respect lawmakers’ will if they voted to lift the measure.

Yoon's presidential powers were suspended when he was impeached Dec. 14, and South Korea's Constitutional Court is nearing a decision on whether to formally remove him from office or dismiss the Assembly’s impeachment and reinstate him.

Martial law was lifted about six hours after Yoon declared it but has caused political turmoil, disrupted high-level diplomacy and tested the resiliency of the country’s democracy. Yoon’s conservative supporters rioted at the Seoul Western District Court after it authorized his arrest last month, while his lawyers and ruling party have openly questioned the credibility of courts and law enforcement institutions handling the case.

Yoon has continued to express contempt for his liberal rivals for obstructing his agenda and endorsed baseless conspiracy theories about election fraud to justify his ill-fated authoritarian push.

Yoon’s defense minister, police chief and several military commanders have also been arrested and indicted on rebellion, abuse of power and other charges related to the martial law decree, which involved hundreds of heavily armed troops deployed to the National Assembly and National Election Commission offices.