On April 18, 1948, a couple of weeks after the start of the armed uprising, Military Governor Dean gave an order to Lieutenant Colonel Mansfield. That order directed LC Mansfield to do several things. The key orders were that LC Mansfield was to use the army (constabulary) to suppress the uprising and to make contact with the armed resistance group and convince them to surrender before beginning any military operations. Mansfield attempted to get several different people within the Jeju government to begin this task, but was unsuccessful. In the end, he order Kim Ikryeol (김익력) to contact the armed resistance group.

On April 22, Kim Ikryeol dropped letters from an airplane. In the letter he decried the "fratricidal war" and requested a meeting with the armed resistance group. In a response they agreed to meet with him and sent him instructions. Kim Ikryeol reported this to LC Mansfield and received the following instructions:

1. Kim Ikryeol represented MG Dean

2. Those in the armed resistance who had killed someone or committed arson would be pardoned (from the death penalty)

3. All other lesser crimes would be completely pardoned

4. MG Dean would be in charge of implementing the agreement

5. The armed resistance would immediately cease attacks, surrender all weapons, and submit a list of all offenders and their crimes.

On the morning of April 28, the meeting between Kim Ikryeol and Kim Dalsam (김달삼) began in Gueok-ri, Daejeong-myeon (대정면 구억). After much discussion the two agreed on the following: a

1. All fighting should stop within three days (due to communication problems)

2. The armed resistance will disarm gradually (in case the agreement breaks down and fighting resumes)

3. Armed resistance members in the mountains that peacefully surrender will not be harmed

4. Any surrendering armed resistance member will be put in a camp in Moseulpo or Jeju City (and later Seogwipo or Seongsan) and that no police may access those camps.

This agreement was presented to LC Mansfield who was reportedly highly satisfied with it. Unfortunately, three days later an incident in Ora-ri (오라리 방화 사) would see this agreement fall apart and any hope of preventing further bloodshed with it.

References

The National Committee for Investigation of the Truth about the Jeju April 3 Incident - "The Jeju 4.3 Incident Investigation Report" (downloadable here in English)