Who is the murderer in the Itaewon murder case?

Both of them were murderers and they killed each other together. When the black owner of the bar testified, Alex said while drinking, "We just stabbed a person in the neck." What he said was "We ", it should be him and Pearson. Alex gave a gift to his lawyer. The moment he entered the elevator, his idiom appeared, I will show you sth cool, come with me! It echoes the opening chapter, and then the lawyer’s expression, if you look closely, you will find that it is an expression of regret and regret, and then there is the conversation between Pearson and his lawyer. The moment the lawyer said that he could speak Korean, his expression had a brief moment. Freeze, eyes began to blur, and finally said that Korean was not learned in prison, which shows that he had deliberately concealed it before, pretending not to know, and then used the identity of a foreign immigrant to make the investigation more difficult. The two corrected each other, so that they were not present The appearance of eyewitnesses forced the entire investigation process to rely on reasoning and argumentation, and in the end it was no choice but to resort to scenario simulation to recreate the situation. . . Moreover, during the escorting process in the prison van, neither of the two people accused each other. Pearson may be rich, but Alex's character, if it was really not him, a quarrel would be inevitable. At the moment when he was upset, I wondered if he was upset because he had not been able to successfully escape guilt.