(if you have played Danganronpa: Trigger Happy Havoc then you know that Mukuro Ikusaba was dressed as Junko Enoshima from the beginning.)

Out of costume:

Name: Mukuro Ikusaba
Gender: Female

Ultimate Soldier
Form of death: Murdered

Autopsy:
Mukuro Ikusaba died almost instantly due to bloodless, she was killed by her own sister. She was impaled multiple times by spikes going through her chest, stomach and legs. There was no trial held for her and she left no evidence behind. The culprit was considered Monokuma at the time and not Junko Enoshima.