It has to be someone that is a superior to Anan Yuki, who is a top public prosecutor.
The age range of the killer is someone between 40 to 60 years old because it's been about 21 years since the case happened.
I think the old dude is called Narukawa, he might be a candidate because he used to be a prosecutor and the way he shouted at Kamii, kinda frightening.
The backpack with the blue carabiner(it's a rock-climbing hook), it has to be someone that is rather active, wealthy or comes from a wealthy family to have that kinda power over people.
I'm so damn curious.
