Yoon Jae Moon suspected Park Yoo Chun as the president's assassin.
On the 2nd episode of SBS Wednesday/Thursday drama "Three Days" (script Kim Eun Hee, director Shin Kyung Soo) broadcast on the evening of March 6th, President Lee Dong Whee (played by Son Hyun Joo) disappeared after three shots were fired.
On this day, Han Tae Kyung heard about the attempt at presidential assassination and to notify this, he looked for the bodyguard director Ham Bong Soo (played by Jang Hyun Sung). However, he had already submitted his ID and this wasn't easy to approach.
During this time, the assassins of President Lee Dong Whee tried to bomb an EMP near the vacation home and attempted assassination. After three shots, President Lee Dong Whee was nowhere to be found and Han Tae Kyung reported this fact to the officer of the military Yang Dae Ho.
However, after checking Yang Dae Ho's CCTV, the only person in the house was Han Tae Kyung, and thus he was pushed to be a suspect.
Shin Kyu Jin (played by Yoon Je Moon) said, "The Presidential bodyguard chambers are secure. It's impossible to pierce through this and to get in." Ham Bong Soo asked, "Are you now suspecting the bodyguards?" At this, Shin Kyu Jin said, "No. I'm suspecting Han Tae Kyung" and suspected that he squandered confidential internal information.