Before dawn on Wednesday, 3,000 police officers arrived at the heavily guarded official residence of South Korea's suspended President Yun Seok-yeol.

Their mission: arrest him.

Investigators used ladders to climb over buses and anchor cutters to cut through barbed wire as they breached multiple blockades designed to stop them. Others hiked along nearby trails to the presidential palace.

They arrested him hours later.

This is their second attempt. The first occurred earlier this month, when about 150 police officers were locked in a six-hour standoff with the president's security detail.

They were helplessly outnumbered, first by the large number of pro-Yin supporters who gathered outside his residence to hold back the police, and then by the wall of security personnel inside the residence.

Ultimately, investigators concluded it was "virtually impossible" to arrest him and walked away.

In many ways, Yoon is now a disgraced leader—impeached and suspended from the presidency while he Awaiting the ruling of the Constitutional Courtwhich could unseat him.

So why was it so difficult to arrest him?

It has been an unprecedented few weeks for South Korea since Yoon Eun-hye issued a shocking but short-lived martial law on December 3.

Lawmakers voted to impeach him, a criminal investigation ensued, and his refusal to appear for questioning prompted an arrest warrant.

A key obstacle to arresting police officers was President Yoon's security team, which formed a human wall on January 3 and used vehicles to block the police's path.

Analysts said they may have acted out of loyalty to Yun, noting that Yun himself appointed several Presidential Security Service (PSS) leaders.

"Yin may well have cultivated hardline loyalists within the organization to prepare for this eventuality," said Christopher Jumin Lee, an American lawyer and Korea expert.

It's unclear why their resistance weakened this time, but Mr Lee believes the team may have been intimidated in part by the "overwhelming display of force by the police".

"Ultimately, I think they were just unwilling to engage in the massive violence against law enforcement officers that would be required to fully defend Yin," he said.

Earlier this week, the chief information officer warned the Department of Public Safety that they risked losing their pensions and civil service status for obstructing an arrest.

By contrast, it assured those who "disobey unlawful orders" to prevent arrests that they "will face no disadvantage".

On Wednesday, Yonhap News Agency reported that several PSS members were either on vacation or had chosen to stay at their official residences.

In addition to his security, the right-wing leader also enjoys a strong support base. Some of his supporters earlier told the BBC that they Prepare to die to protect him and repeatedly made baseless accusations that Yoon himself had surfaced, including that the country had been infiltrated by pro-North Korean forces.

On January 3, thousands of people braved the freezing cold and camped outside his home to prevent the arrest team from entering. They cried with joy when they found out the arrest team had given up.

A similar scene unfolded on Wednesday, when large crowds of pro-Yin supporters showed up, some of whom violently fought with police to prevent arrests.

Some people cried after hearing the news of Yin's arrest.

But the organization that is really getting attention is the Corruption Investigation Office (CIO), which is jointly leading the investigation with the police.

Some have questioned why Yoon was not arrested on the first attempt, with critics accusing it of poor preparation and lack of coordination.

The agency was created four years ago by the previous administration in response to public anger against former President Park Geun-hye. Park Geun-hye was impeached, removed from office and later jailed over a corruption scandal.

Mason Rich, an associate professor at Hankuk University of Foreign Studies in Seoul, said this month's failed attempt was a "further blow" to CIOs who "already don't have a good reputation for political and competency reasons."

Associate Professor Rich said CIOs were likely to view today's successful arrest as a victory, but it remained to be seen how they would handle the ensuing investigation.

"Many people don't believe the information they're being conveyed about the investigation," he added.

Lee Chang-min, a lawyer and member of the Lawyers for a Democratic Society, said, "We are stuck in this chaotic situation after various organizations scrambled to take the lead in the investigation for their own benefit."

"Even if the joint investigation agency is retained, the case should be handed over to the police, who should maintain their authority," he added.

In fact, the CIO does not have the authority to bring charges against Yin, and the case is expected to be handed over to state prosecutors after an investigation.

Yin's lawyers also argued that the CIO, as an anti-corruption agency, did not have the authority to investigate the insurgency allegations against Yin.

South Korea is now in uncharted territory, with Yoon being the first sitting president to be arrested.

Mr Lee said the investigation into him had also "mobilized far-right populist elements within the conservative coalition" who could have "a huge impact" on the future of conservative politics in the country.

Additional reporting by Koh Ewe