Spoiler for the red text:
After Jessica was injured, Eva was always under Battler's supervision.
Battler is neither the culprit nor an accomplice.
By this, we can establish a perfect alibi for Eva
There are no more than 18 people on this island
No life forms other than humans have any connection to this game
Kinzo is dead
Krauss is dead
Natsuhi is dead
Hideyoshi is dead
George is dead
Rudolf is dead
Kyrie is dead
Rosa is dead
Maria is dead
Genji is dead
Shannon is dead
Kanon is dead
Gohda is dead
Kumasawa is dead
Nanjo is dead
The 15 people mentioned are dead
Battler is alive
Eva is alive
Jessica is alive
Eva was with you the whole time.
So committing a crime was impossible for her.
Of course, Battler-kun isn't the culprit.
He wasn't forging an alibi for her, and he took the possibility that she was the culprit into account, watching her actions carefully.
No chance existed for her to do anything suspicious!
In short, at the time of the crime, only Nanjo and Jessica were in the servants' room
Ushiromiya Jessica has not committed murder
She was not involved with Nanjo's murder
Her eyes were completely blocked.
It's impossible for her to carry out a murder like that
Neither Eva nor Battler killed Nanjo, nor were they involved
The culprit who killed Nanjo was neither Battler nor Eva nor Jessica
Jessica's eyes were completely blocked, and murder was impossible for her
No actions caused by Jessica's body had any relation to or influence on the murder of Nanjo
This also applies to Battler and Eva
neither Jessica nor Battler nor Eva is the culprit who killed Nanjo
Nanjo was killed by another person
Of course, it was with a direct method of murder, not a trap
A weapon was readied, and he was killed with it from point-blank range in front of him!
The culprit appeared openly before Nanjo's eyes, and as they both looked at each other's faces, the culprit killed him
The red only tells the truth
Absolutely no factors other than humans participate in this game board
The one who killed Nanjo was definitely a human
A human, with their feet on the ground, held up a weapon and killed with it!
Right before his eyes!
So basically, the only way to logically explain this situation, is to assume that someone is impersonating for one of the mentioned 15 dead characters and the original is dead.
We know that Gohda was hired just before, or right after, Kinzo death and that he was chosen because of the best qualifications.
If a person X would suspect that Kinzo is dead, or soon will be, and wanted to steal his fortune, he would probably send a spy on the island. The real Gohda was killed right after he was fired from the hotel and his identity was stolen by the spy who use it to infiltrate the The Rokkenjima.
I personally find “Gohda” extremely suspicious because his death was never 100% certain. In the first episode his face was destroyed, in the second and third Battler did not find his body and in the forth episode his face was all covered in blood. The way that “Gohda” and Kumasawa corpses were placed in episode 4, visible but unreachable, suggests that the culprit wanted to show them in the open to trick the witness. In the end Battler found the way to examine them, but because he didn’t clean the blood on their faces (and because
Battler is incompetent), we can’t be certain that those bodies really belong to “Gohda” and Kumasawa.