[jeroz]

Once I saw that weapon I hate myself for randomly stumble over one particular fan art last year which links one character with it.........

Anyway even with the culprit most likely to be that person let's see if I can piece all the clues up together. Firstly without reading any other hints Klash put in the spoiler above.

Spoiler for deduction time:

First of all, Syo's name being brought up in a series that can't waste any time means that it's obvious it will be the actual person himself. The fact that they term drop "double personality" make it more obvious that it's the "most unlikely source" possible. Monokuma knowing the past history of this person means that the killer has a very strong reason to get out of this place before it gets leaked. As such Fujisaki might be just another unfortunate soul who got caught up in this mess.

As for the method,
Firstly the swapped wallpaper. After the previous case it's likely the fact that someone swapped the two posters in order to cover up something. Perhaps the reason why they were changed is the fact that she was killed in the male changing room. Look back to the scene where Sakura dropped her protein shake, the poster are the boys. Here's another question though. Is Fujisaki actually female? I know that it's a contentious point on the internet so far, but I'm not too sure how much I should see it as being complete bs just for fun.
EDIT: Just saw those screwdrivers near "her" at the 15th minute. Yep, too cute, must be a boy. I guess Monokuma also knows about it.
Edit2: Actually....did the anime actually specify that the girls don't have the toolset?

The carpet being cleaned means there's something else on there that the culprit wants to hide. Either the blood or some unknown factors. What's interesting is the fact that there are still blood on the carpet, meaning that for some reason the culprit clean the carpet first, and then possibly hit the victim in the head in order to create a false impression. With Sakura being the only buff person in the lineup, she's most likely to be innocent anyway. For sake of simplicity I'll trust the autopsy report for now that the cause of death is blunt trauma to the head. Having said that it doesn't necessarily rule out the weaker looking characters though as the killer could just grab Fujisaki's head and bang it against the weapon. However if that's the case then 1) how did the murderer move the weights, 2) why is it necessary to change rooms then? Then again it's highly unlikely that the culprit wants to splash the blood onto the wrong poster to create a false lead, so that much be an accident.
Edit: Perhaps the carpet was also changed as well?

The missing bag and the fact that Fujisaki was hiding it points to another hidden agenda in the victim. Her special skill being a hacker opens up an possibility that she tampered with the ID possibly to change the files with someone else. The bag either was still at the site of the crime, or the killer took it away somewhere else since there's something in it. The gym uniform can mean either a simple cover up for something else or she was in her uniform earlier. I wish Celes give us more information as to whereabout, than just "oh i saw her like that". The ID being used only for the changing room so far means that it's highly likely that the culprit has Fujisaki's ID. Just because the rule says that you can't borrow it to other people doesn't mean that you can't grab it from others. I'll assume that the rule about no multiple entries with one swipe is also notified to everyone. The killer could just open once, throw the body in, open again, and walk in.

The big question would be why would Syo recreate the same scene of the crime over and over again, especially this time. I feel like the story made it too easy by removing the possibility of a copycat. Then again, this could still be a red herring, but i'll run with it for now. Even with that case there are two reasons: compulsive disorder, or to create a false alibi by making a false negative. I just don't get this part. Maybe he's covering up for something?

There are a few points which I don't know is suppose to happen or just narrative choice to hide the answer away from the viewers. One being Kyouko observe Fujisaki on the belt, and the other one being the blank student ID. As much as I appreciate those new interactions between the characters, I feel kind of annoyed that the anime didn't give us more so I can gauge what Fujisaki is like other than being timid. Unlike Sayaka I doubt she will want to kill anyone at the moment, and not much evidence yet points to it either. Chances are that she found out who Syo is, and got into a scuffle and died in an accident which Syo used the opportunity to set up a murder scene. Actually with those deductions I

Also since it's still the 2nd case of the game, I doubt those that helped the MC will be lying or being the culprit, otherwise it would be too overly complicated. Also that both the biker and the prefect have perfect alibi, unless one fainted and the other one just pretend nothing happened. Having said that, I'm liking those two probably a bit too much at the moment and would hate to see bad things happen to either of them. It would be fun though if Togami is the killer since he helped(miguided) the MC to think that someone else is the murderer.

Edit: So in conclusion
Fujisaki is not a random bystander, and also a boy. He's most likely killed in the male changing room.
(Question: How did the killer get in with him?) - either manipulation of the ID card through physical transfer or electronic tampering by Fujisaki. Most likely a case of Fujisaki opening the door again. Monokuma didn't prohibit invited entry.
After that he got dragged to the female changing room, along with the poster, and possibly the carpet as well. Now this would imply that the killer is able to get into both room even with the restriction of the machine gun. Actually, does the machine gun really point to the door of the male changing room or just the female one?
The bag probably contain the wires which was used, and the bag was brought by Fujisaki and later thrown away somewhere else.
(Question: why is he bringing a bag?) - that i have no clue...
(Question: why is one of the ID blank though?) - it's highly unlikely that it's Fujisaki's ID, otherwise it'll be boring. The culprit most likely has his ID.

As to who the culprit is, it's easy to do a body search, but as to get a proper accusation.....Unlike
I'm still putting the pieces up...I feel like there are things that I haven't seen yet. As you can see, everything is a mess right now.

My brain needs a break, I'll post another one once I clear my head more