Detective Conan - Vol. 5 Ch. 41 - The First Victim!

[MangaDex]

 

[zephyrnepres]

They're in a film club together. I guarantee that a few of them are in on it (likely Ayako since she does makeup and costumes, possibly with Chikako working with her to design the 'bandaged man' character) and that the body is just a well-made dummy or something. Also, Oota's figure fits with the bandaged dude better than any other character and his role is supposed to be the 'main character'. I reckon he's the bandaged man.
EDIT: My theory is that a few of the members blame one person for the suicide of their friend and are trying to scare them into confessing or something along those lines.

 

[Rulasian]

this chapter has been surprisingly explicit.

 

[randoms986]

Brutal, dude had one hell of a grudge.

 

[Late_Komei]

One of the few time you see a corpse so mutilated in Detective Conan.Damn!