Why is it so hard to arrest South Korea's impeached president?

Police officers remove supporters of impeached South Korean President Yoon Suk Yeol from outside his official residence in Seoul

There were more than 100 police officers and they were armed with a warrant, but South Korean authorities failed to arrest suspended President Yoon Suk Yeol after a six-hour deadlock outside his home.

That's how long the confrontation with Yoon's security team lasted as they formed a human wall and used vehicles to block the arrest team's path, according to local media.

It has been an unprecedented month for South Korean politics. Yoon's shocking yet short-lived martial law order was followed by an impeachment vote against him. Then came the criminal investigation, his refusal to appear for questioning and, earlier this week, a warrant for his arrest.

The right-wing leader still has a strong support base. Thousands of them turned up outside his home on Friday morning to oppose his arrest.

But, by many accounts, Yoon is now a disgraced leader - impeached by parliament and suspended from office, he awaits the decision of the constitutional court which can remove him from office.

So why has it proven so difficult for police to arrest him?

The men guarding the president

Although Yoon has been stripped of his presidential powers - after lawmakers voted to impeach him - he is still entitled to a security detail.

And those men played a key role in blocking the arrest on Friday.

The presidential security service (PSS) could have acted out of loyalty to Yoon or under "a misguided understanding of their legal and constitutional role", says Mason Richey, an associate professor at Seoul's Hankuk University of Foreign Studies.

Anti-Yoon protesters clash with police after investigators failed to arrest the suspended president

Given that Yoon has been suspended, the PSS should be taking directions from acting President Choi Sang-mok. "They have either not been instructed by acting President Choi to stand down, or they are refusing his orders to do so," says Assoc Prof Richey.

Some experts believe the security officers were showing "unconditional loyalty" to Yoon, rather than the office itself. They point to the fact that the PSS's chief Park Jong-joon was appointed to the job by Yoon last September.

And that Park's predecessor was former defence minister Kim Yong-hyun, who is accused of advising Yoon to impose martial law. He is currently being held for questioning as part of the criminal investigation into Yoon.

"It may well be the case that Yoon has seeded the organisation with hardline loyalists in preparation for precisely this eventuality," says US-based lawyer and Korea expert Christopher Jumin Lee.

A risk of escalation

The "simplest" solution, Mr Lee says, is for acting president Choi to order the PSS to stand down in the interim.

"If he is unwilling to do so, that may be grounds for his own impeachment by the National Assembly," he added.

Choi, who is the finance minister, had stepped in to lead the country after lawmakers voted to impeach Yoon's first successor, Prime Minister Han Duck-soo.

This political stalemate also reflects the polarisation in South Korean politics between those who support Yoon, and his decision to impose martial law, and those who oppose it. And the differences don't necessarily end there.

The vast majority of South Koreans agree that Yoon's declaration of martial law on 3 Dec was wrong and that he needs to be held accountable, says Duyeon Kim, an adjunct senior fellow at the Center for a New American Security, but they cannot agree on what accountability looks like.

"The actors involved disagree over process, procedure and their legal basis, which is adding to the current political uncertainty," she explains.

That uncertainty is also creating tense standoffs like the one that unfolded on Friday in and outside Yoon's presidential residence, where his supporters have been camping out for days, leading to heated speeches and even skirmishes with police.

Law enforcement could return with more agents and use force but that would be "highly dangerous," Assoc Prof Mason said.

South Korean President Yoon Suk Yeol

The PSS too is heavily armed, so arresting officers would be looking to avoid any escalation.

"What happens if the police show up with additional warrants calling for the arrest of PSS personnel, [the PSS] defy those warrants as well and then brandish their guns?" Mr Lee asks.

Police have now said they are investigating the PSS director and his deputy for obstructing them - so there could be more charges and arrest warrants coming.

The fallout from Yoon's martial law order is also a challenge for the Corruption Investigation Office (CIO) that is investigating him.

It has only been operating for four years. It was created in response to public anger over former president Park Geun-hye who was impeached, removed from office and later jailed over a corruption scandal.

While South Korean presidents have been jailed before, Yoon is the first one to face arrest before he steps down.

Investigators have until 6 January to arrest Yoon before the current warrant expires.

They may attempt to arrest Yoon again over the weekend, although the weekend could pose a bigger challenge if the crowds of supporters grow. They can also apply for a new warrant and try to detain him again.

Given how far South Korea has now slid into uncharted territory, the uncertainty is likely to continue.

Additional reporting by Ewe Koh