South Korea's ex-president Yoon given 5-year jail term in first ruling over martial law

The Seoul Central District Court found Yoon guilty of mobilizing the presidential security service to block authorities from executing an arrest warrant that had been legally issued by a court to investigate him for his martial law declaration.

In televised proceedings, he was also found guilty of charges that included fabricating official documents and failing to comply with the legal process required for martial law.

The ruling is the first related to the criminal charges Yoon faces over his botched martial law declaration.

"The defendant abused his enormous influence as president to prevent the execution of legitimate warrants through officials from the Security Service, which effectively privatized officials ... loyal to the Republic of Korea for personal safety and personal gain," the lead judge on the three-justice panel said.

Speaking outside the court immediately after the decision, one of Yoon's lawyers, Yoo Jung-hwa, said the former president would appeal the ruling. "We express regret that the decision was made in a politicised manner," she said.

He could face the death sentence in a separate trial on a charge of masterminding an insurrection by declaring martial law without justification.

Yoon has argued it was within his powers as president to declare martial law and that the action was aimed at sounding the alarm over the obstruction of government by opposition parties.

Yoon, who also denied Friday's charges, could have faced up to 10 years in jail over the obstruction charges related to when he barricaded himself inside his residential compound in January last year and ordered the security service to block investigators.

He was finally arrested in a second attempt involving more than 3,000 police officers.

Yoon's arrest was the first ever for a sitting president in South Korea.

Parliament, joined by some members of Yoon's conservative party, voted within hours to overturn his surprise martial law decree and later impeached him, suspending his powers.

He was removed from office in April last year by the Constitutional Court, which ruled he violated the duties of his office.

While Yoon's bid to impose martial law lasted only about six hours, it sent shockwaves through South Korea, which is Asia's fourth-largest economy, a key U.S. security ally and long considered one of the world's most resilient democracies.