Former President Yoon Suk-yeol returns home after completing an investigation as a suspect at the Office of Special Prosecutors for Insurrection, established at the Seoul High Prosecutor's Office in Seocho District, Seoul, early in the morning on the 29th. /Courtesy of News1

Former President Yoon Suk-yeol's side is set to submit an opinion letter to Special Prosecutor Jo Eun-seok's special investigation team on the morning of the 30th, requesting compliance with due process during the investigation.

Yoon's legal representatives said on the 29th, "We request that the special prosecutor ensure that due process in the investigation is guaranteed by referring to the opinion letter."

The legal representatives also cited the summons request and the installation of a photo line, which allegedly did not involve discussions with the lawyers, claiming that "the second summons request was also an unilaterally issued text message notification without any discussions."

Park Ji-young, deputy special prosecutor of the special investigation team, stated regarding future summons schedules, "Consultations do not equate to agreements. Decisions are made by the investigative authorities." The legal representatives responded to this statement by questioning, "Does the special prosecutor disregard the law or is it ignorance of the law?" and added, "There were neither agreements nor consultations." They further remarked, "The announcement of multiple summonses at any time goes against the principle of voluntary investigation and constitutes a violation of the laws regarding investigations."

Yoon's side reiterated concerns over Chief Detective Park Chang-hwan of the Korean National Police Agency's serious crime investigation division overseeing the investigation, stating that "the identity of the investigative authority is ambiguous and the form does not comply with the Criminal Procedure Act," and requested clarification on whether it was a record prepared by a judicial police officer or one prepared by a prosecutor before determining the investigating authority and attendees according to the appropriate form.

The legal representatives continued, "The police claim that Chief Detective Park visited the scene to execute the arrest warrant for former Vice Administrator Kim Sung-hoon, so it has no relation to the execution of an arrest warrant for former President Yoon, but the warrant for former Vice Administrator Kim also involves the same legal issues," adding, "Chief Detective Park is a direct party to the case."

They asserted, "(The special prosecutor's investigation) is clearly an unrelated case investigation, an unlawful investigation," and argued that, "Rather than focusing on investigating individuals related to the insurrection charges, the largest-ever special investigation team being preoccupied with securing new recruits through unrelated investigations is not only contrary to the purpose of the special investigation, it appears quite miserable in light of its scale and power, and is merely a manifestation of anxiety over performance."

The special prosecutor completed the first face-to-face interrogation of former President Yoon on the 28th and notified him to appear again on the 30th; however, considering various circumstances on that day, they then notified him to appear on July 1.