Trying to tie this person into our suspect, I wonder the following:
Regarding the scar on the back of the left hand in the photo above, it’s been said that the killer is thought to have severely wounded the palm of his hand. I can’t remember if it’s known which hand. How does that fit with this scar?
Where did the information about the palm wound come from? I believe LE thought he had a palm wound based on the bloody handkerchief (and maybe something else?) Was the hand wound of the man on the subway a palm wound? If so, could there actually have been two severe hand wounds, but the subway observer only saw one? If there were TWO severe hand wounds, wouldn’t that have been noted and described? Something like “his hands were all cut up”?
Also, I can’t remember if the subway observer said it was the palm. I’ll have to go back and look. Anyway, if there is an additional hand wound, a palm wound, is there a way to confirm such on the man in the photo above?
And, the obvious question? Is it possible to obtain DNA surreptitiously?
ETA: I’m probably using the incorrect term of subway. I think train is correct.
Nobody knows exactly what kind of scar he would have. According to the Chief, his gloves were in a bad way. Gloves, plural. Unless there was a translation issue, it sounds like across three stabbings and two knives, he probably injured both. He looks right-handed to me from photos. But I'm only judging that from one where he's holding a tennis racquet (though as I say above, there are players who practice with their weaker hand).
If you hold a knife in your left hand and (carefully) let it slip, it does end up hitting the area in which he has the cut. But consider that he clashed violently with Mikio who had many defensive wounds, plus they were on the stairs with the killer above and Mikio below, it's hard to know or divine exactly how the knife was hitting and how the killer would have subsequently injured his hands. He also broke his knife off in Mikio's skull but carried on stabbing with the broken knife AND then carried on stabbing with the carving knife after pausing. All of that to say, it's quite possible he had already hurt his right hand but knew he needed to finish the job and switched to his right. Or vice versa.
As for the "wounded man" in Tobu-Nikko station (several hours north of Tokyo), we get into that in the podcast. Basically, he's a mystery. I don't know exactly where on his hand he was injured but from what I heard the bone was exposed which caused significant alarm at the station. Yet he seemed reluctant to go to the hospital. That's the story, anyway. None of it has been verified and when we approached the train company, they refused to comment "by request of the Tokyo MPD". But frankly, the TMPD seem confident he had nothing to do with these murders. I do know that the cops interviewed hundreds of men in the following days with hand injuries. I pressed the Chief on why the man in Nikko wasn't investigated immediately or how anybody describing the injuries over the phone could have known enough to rule a person in or out. But he wouldn't elaborate. Only he seemed sure it was a non-starter.
So, I think the injury to the killer's hand is based on his shredded gloves, the significant amount of blood he lost, and the fact he went through the family's entire first aid kit.
And by obtaining DNA, do you mean at TN Station? One interesting point, while it's not yet legal in Japan to use DNA in the way that it is in the USA or Europe, there is an exception. If the family of the victims own the house where the murder occurred, technically the killer's DNA at that property belongs to them and they're free to do with it what they will. This would include sending it abroad to Parabon, Othram, etc. I can't get into too much detail here but a certain relative declined to pursue this... Make of that what you will.
