Forgot to add Havoc10K being killed ....
Oh, sorry looks like you're right... Well, here then I'll expand on some things:

Day 2 news said there was Demon activity, so Arc is innocent.
Scotsman could be the Demon and SeventyX7 could be either killer. Since we know the Demon wasn't boxed or killed, this means that on Day 3 due to the "spiritual pressure dropping pretty hard" either the Demon got Feedback (which could have also occurred on Day 2), or was the tortured scotsman. "We're still having trouble reattaching one of his toes . . . We expect the toe to be back to normal within a few days. The other removed limbs, digits, finger nails and skin seem to have recovered nicely. As good as new!" Either scenario is obviously possible.
It's impossible to know about Borror0 since there is no data.
All this shows is that the ones mentioned above
could be the killers, but it does not rule out the fact that they also
could be innocent. It also neglects the fact that
anyone that wasn't questioned could be the killers as well.
There are a ton of clues in the news, some specific ones I mentioned where to look a couple posts ago. I'll also say that there are no inactive players as Killers. So:
Could not be Killers:Arc Da Rat
harpy
Havanacus
pmDarkly
tomoya-kun
Could be Killers:shabutie - Claims to be Tertiary Adjunct
Teaparty - Claims to be Grand Inquisitor
SeventyX7
scotsman
saidin1015
flyawave
suhaib
vuzedome
Meomix
1000mAh
TightMuffin
Klocknov
Borror0
So, if you also eliminate the two that claimed to be roles (though they certainly haven't been proven), that means there are 11 possible candidates. That means based on sheer luck alone, you have a 9% chance of guessing who the killer is.
However... if you look at the clues I gave you, the possible choices drop down substantially. The single biggest clue that will cut out the largest pool of players is this: "You're all a bunch of mindless sheep
being manipulated by the very criminals you're trying to apprehend, if you're even trying in the first place." Which, was seen in Day 4 Night Scene 3.
So, if this is true and at least one of the killers is a player that has been very vocal and actively influenced player voting, how many choices do you have?
If you follow this advice and determine which players have done this, and there are very few of them, you will have an extremely high chance of boxing at least one killer tonight. I would say out of the above, there are likely 3 that have done this. You can figure out who they are. And that being the case, that means if voting based on this, there is a 1 in 3 chance of taking out a killer.
Of course, when it's down to that, examine the other clues. I bet you can actually get it narrowed down to 2 or even 1. And that would be what I'd call extremely good odds.