The man central to blocking investigators from arresting South Korea's impeached President Yoon Suk Yeol has come under the spotlight himself in the political crisis sparked by Yoon's brief declaration of martial law last month.
Park Chong-jun, who reports directly to Yoon, was instrumental in rebuffing the investigators' attempt on Friday to serve an arrest warrant on Yoon, resulting in a six-hour standoff in Yoon's official residence.
Presidential guards and military troops prevented authorities from arresting Yoon for alleged insurrection on the warrant, which is valid through Monday. The anti-graft body that is leading the investigation with police said on Friday it was working out its next steps.
Yoon's Dec. 3 declaration of martial law stunned South Korea and led to his impeachment and suspension from duties on Dec. 14. The president's political fate is in the hands of the Constitutional Court.
His legal fate is being fought over by an array of law enforcement agencies against Yoon's forces - with Park in a pivotal position.
Appointed by Yoon in September, Park had already played a role in preventing investigators from executing search warrants for the president's offices and residences, citing national security.
"The Presidential Security Service exists solely for the absolute safety of the security target," Park says in a message on the service's website, adding that its mission to protect the president "at every moment" must leave no loopholes.
He employed that rationale to rebuff Friday's efforts to arrest Yoon, on the grounds that investigators were exceeding the bounds of security laws and injuring some security service staff.
'OUT OF CONTROL'
Critics worry that it is Park's service that is being excessive.
"The presidential security service is a dangerous institution whose power can go out of control," said Han Seung-whoon, a professor of police administrative law at Dongshin University.
"Since only the president has the authority to control it, the security service can abuse the power and turn into the president's private army."
The anti-graft body, the Corruption Investigation Office for High-ranking Officials (CIO), said it had to call off Friday's arrest attempt because of fears over the safety of its personnel.
Yoon's security service and troops under its control outnumbered the arresting officials, the CIO said. At one point, it said, Yoon's people linked up in a human chain of about 200 to block access to Yoon and his official residence, while buses and military vehicles were also used as blockades.
On Friday, the police said they would investigate Park for potential obstruction of justice, asking him to appear for questioning. He declined for the moment, saying he could not be away from work even for a moment at this critical time.
Park and his deputy were in talks to provide a response to the investigators at a future date, the security service said.
The police on Saturday asked for him to appear on Tuesday.
Yoon's lawyers contend the CIO lacks the authority to investigate insurrection, rendering the arrest warrant illegal.
A court approved the warrant, the first against a sitting president, on Tuesday after Yoon ignored repeated summonses for questioning.
CONTROVERSIAL HISTORY
Critics of the presidential security service call it a relic from the days of South Korea's strongman leaders, who ruled until the late 1980s.
It was placed under the president's direct control during the days of military rule in the 1970s and 1980s, and headed by loyal aides who wielded immense power.
After the 2016 impeachment of then-President Park Geun-hye, lawmakers, calling the service the "brainchild of authoritarian military regime", proposed changes to transfer it to a police agency.
They also sought to downgrade the rank of its chief, but the reform efforts appear to have been stalled.
Park's predecessor in the presidential security service is Kim Yong-hyun, a close ally of Yoon, who left the role in September when he was appointed as defence minister.
Kim has since resigned the latter post and was indicted on insurrection charges, accused of a key role in recommending and preparing for the martial law attempt.
The declaration, which Yoon rescinded six hours later when the opposition-controlled parliament defied him, outlawed political activity and sought to control the media.
Park, a former senior police official who failed in two bids for parliament in 2012 and 2016, graduated at the top of his class at the Korea National Police University, rising to become deputy chief of the national police agency in 2011.
In 2012 he helped the conservative Park Geun-hye in her successful presidential bid, then became deputy chief of her presidential security until 2015.
At the time of Park Chong-jun's appointment to head the presidential security service, Yoon's chief of staff said he would help build "an advanced security system".
The opposition has demanded his arrest for blocking Yoon's arrest and urged an investigation into his alleged role in the martial law declaration.
Previously questioned as a witness in the investigation of that declaration, he denied the allegations, according to media reports.
