This post gives more details of the South Korean police state around the time of Park Chung-hee’s assassination in 1979.
An Irish priest talks about his observations of South Korea before and after the assassination of Park Chung-hee. Ample video links are provided for a good picture of the times.
In this 2007 interview, a western banker shares his experience of arriving in South Korea the day after Park Chung-hee was shot and doing business in the police state of that time.
This is a 1991 interview with an Irish Catholic priest, a longtime resident of South Korea, on the subject of human rights and the 1980 massacre in Kwangju (Gwangju).