[2] There is a great deal of controversy surrounding Kim's motives; it remains uncertain whether the act was part of a planned coup d'état or was merely impulsive.

[4] Almost immediately following its creation, the KCIA was used to suppress any domestic opposition to Park's regime, including wiretapping, arresting, and torturing without court order.

The KCIA was heavily involved in many behind-the-scenes political maneuvers aimed at weakening opposition parties through bribing, blackmailing, threatening, or arresting opposing lawmakers.

Additionally, it gave the president the authority to suspend the constitution and issue emergency decrees, appoint all judges, and dismiss the National Assembly.

[7] On October 16, when it became known that the government was planning to accept the resignations selectively, democracy protests broke out in Kim's hometown of Busan, the second largest city in South Korea, resulting in arson attacks on 30 police stations over several days.

The demonstrations, the largest since the days of President Syngman Rhee, spread to nearby Masan and other cities on October 19, with students and citizens calling for a repeal of the Yushin Constitution.

The KCIA director, Kim Jae-gyu, went to Busan to investigate the situation and found that the demonstrations were not riots by some college students but more like a "popular uprising joined by regular citizens" to resist the regime.

[6] While Park faced increasing opposition to his dictatorship outside The Blue House, another kind of conflict was intensifying inside The Blue House between Kim Jae-gyu, who was appointed KCIA Director in December 1976,[10] and Chief Bodyguard Cha Ji-chul, who was appointed to his position in 1974[11] after Park's wife Yuk Young-soo was killed in an assassination by Mun Se-gwang, an ethnic Korean from Japan.

[13] The rivalry between Cha and Kim was heightened further by a series of political crises in late 1979, as the two rivals clashed over how to deal with growing opposition to the regime.

[16] Cha easily bested his opponent, as his hardline approach was favored by Park; he blamed worsening developments on Director Kim's weak leadership of the KCIA at every opportunity.

[17] On the day of the assassination, Park and his entourage attended ribbon-cutting ceremonies for a dam in Sapgyo and a KBS TV transmitting station in Dangjin.

[20][24] At 6:05 p.m., during dinner discussions of volatile political issues such as the demonstrations in Busan and Kim Young Sam, Park and Cha took a hardline approach.

However, at the moment when Park Seon-ho killed Ahn Jae-song and Jeong In-hyeong, the lights in the entire safe house suddenly went out.

[36] This caused Kang Mu-hong, in charge of repairs at the safe house, who was reading a newspaper in the underground boiler room, to mistake the gunshots for the sound of an explosion when the electricity short-circuited; however, Kang eventually realized that it was not a short circuit upon hearing the gunshots and shouting that continued outside, after which he turned on the circuit breaker again, locked the boiler room door, and hid himself.

[43] As the car passed in front of the Military Manpower Administration, Kim Jae-gyu gave Jeong a square cinnamon candy; he tried to eat it but secretly threw it on the floor, suspecting that it contained poison and could be used by him.

[44] At 8 p.m., Major Song Gye-yong, who was the commanding officer on duty, made an urgent call to Air Force Brigadier General Kim Byeong-soo, head of the hospital who was Park's attending physician since 1974, saying, "A patient with a gunshot wound has been evacuated, but he is D.O.A.

Suspicions were further amplified when Chief of Staff Kim Gye-won was contacted and told to "respectfully take the patient to the president's hospital room."

At 8:30 p.m, when Kim Byeong-soo took off the patient's shirt to check for gunshot wounds, he saw a white spot on Park's abdomen, and only then did he realize that he was the president.

Kim Byeong-soo then went into the medical director's office and called Chun but failed to tell him that the president was dead due to the security guard's surveillance, after which he returned to his room.

However, contrary to Kim Jae-gyu's expectations, the State Council members, including Deputy Prime Minister Shin Hyun-hwak, protested.

Justice Minister Kim Chi-yeol refuted this by saying that such a serious situation cannot be hidden for 48 hours through security for no reason and that the United States should also be informed of this fact.

It made no sense for Deputy Prime Minister Shin Hyun-hwak, who arrived late at the headquarters, to suddenly impose martial law on Kim Jae-gyu; the whole story was as yet unknown.

[46] Finally, Minister of Culture, Sports and Tourism Kim Seong-jin and others protested and demanded a suspension, and the cabinet meeting was suspended.

A cabinet meeting was held at around 11:50 p.m, and Prime Minister Choi Kyu-hah did not mention that the President had died, saying only that 'A serious situation concerning national security has occurred.

[26][49] On the early morning on October 27, at a safe house in Gungjeong-dong, Lee Ki-ju, who was the same age as security guard Yoo Seok-sul, came urgently carrying something.

In the process, Chun Doo-hwan emerged as a new political force by investigating and subordinating KCIA under his Security Command, and Jeong Seung-hwa became the chief martial law administrator.

[52] The Joint Investigation Headquarters ordered the women who attended the President's dinner to use the pseudonyms of Sohn Geum-ja (Korean: 손금자; Hanja: 孫錦子) (Sim Soo-bong) and Jeong Hye-seon (Korean: 정혜선; Hanja: 鄭惠善) (Shin Jae-soon), but the real names were circulated among people and eventually turned out to be true.

The main proponents of the theory that the assassination was unplanned were Kim Gye-won[14] and Jeong Seung-hwa, who had a vested interest in portraying the event as an impulsive act, as they were both suspected of being co-conspirators.

In his last statement at his trial, Kim gave five motives for assassinating Park: "firstly, to restore free democracy; secondly, to prevent further bloodshed of Korean people; thirdly, to prevent North Korean aggression; fourthly, to completely restore the close relationship with our strong ally the United States, which fell to the worst point since the founding of South Korea and advance our national interest through closer cooperation in defense, diplomacy, and economy; and fifthly, to restore [South] Korea's honor in the international community by cleansing the bad image of [South] Korea as a dictatorship country.

Later, declassified U.S. diplomatic cables revealed that Kim was thought of as an unusual KCIA director who often spoke of democracy and as a more approachable figure who often carried Washington's messages on human rights to Park.