Although Islamic historical sources contain many documents and claims about how the murder of 3rd Caliph Hz. Uthman took place, the identity of almost all the names involved in the event is known. In this study, the attitudes of Hz. Ali and Muawiya towards the people involving in the murder of the caliph are discussed. It has been claimed that Hz. Ali, who became caliph after the assassination of Hz. 'Uthman, did not punish those who were involved in the murder of Hz. Uthman, and therefore encouraged and approved of his murder. The most obvious reason for this is the claim that some of those involved in the murder were among those who fought against Mu'awiya in the ranks of Hz. Ali in the events that developed later. Thus, the allegations that Hz. Ali was unable to identify the murderers of Hz. Uthman for various reasons or that he wanted to punish them but had to postpone the matter due to the events that took place are disputed. On the other hand, Mu'awiya's accusation that Hz. Ali, whom he saw as an opportunity to strengthen himself politically on his way to power, had the murderers around him is the dilemma of the issue. For these reasons, the issue has constantly remained on the agenda. In our study, the historical context was taken into consideration with the method of source scanning and the psycho-social aspects of the events were taken into consideration and interpretations were made. In addition to the basic sources on the subject, modern studies were also reviewed and the issue was tried to be handled from a holistic perspective.