The entrance to the presidential residence in Hannam-dong, Seoul, remained quiet on Thursday, the day after President Yoon Suk Yeol was detained on insurrection charges. Yonhap

Police are planning another raid of the Presidential Security Service (PSS) to access encrypted phone servers after detaining President Yoon Suk Yeol on Wednesday. The investigation may expand to include key presidential aides as they seek evidence on Yoon in line with his Dec. 3 martial law, sources said Thursday.

The National Office of Investigation's special investigative team, led by Woo Jong-soo, is reviewing a warrant to search the Samcheong-dong safe house, the PSS and the presidential office.

Investigators believe the encrypted phone server contains records of Yoon's communications with the military, police and top presidential officials during the martial law period. Police argue that these records are essential to prove Yoon's role in the martial law imposition and investigate others in the presidential office.

Earlier attempts to raid the PSS and the presidential office have failed three times. In December, police were blocked while trying to obtain Cabinet meeting records and encrypted phone server data.

Legal provisions under the Criminal Procedure Act, which require consent from the responsible authority for searches in locations involving military secrets, were cited as grounds for denial.

However, police believe the situation may change after Yoon's detention. They obtained warrants to detain PSS Deputy Chief Kim Sung-hoon and Director Lee Kwang-woo before executing Yoon's second warrant on Wednesday but chose not to enforce them.

Supporters rally outside the Seoul Detention Center in Uiwang, Gyeonggi Province, Thursday, as President Yoon Suk Yeol, detained on insurrection charges, skips his second investigation and detention review hearing. Yonhap

The decision was made after both officials pledged to complete their duties as they escorted Yoon to the Corruption Investigation Office for High-ranking Officials. They are also expected to appear for questioning on Friday and Saturday, respectively.

With former PSS Chief Park Chong-jun already questioned, Kim and Lee's anticipated cooperation could mark a shift in the PSS's previously uncooperative stance toward the investigation.

This article from the Hankook Ilbo, the sister publication of The Korea Times, is translated by generative AI and edited by The Korea Times.