Hey so basically this story is based on the reality tv show whodunnit back in 2013
Theres 13 contestants and they are:
Dawson
Sam
Jon
Devin
Andrew
Aimee
Chanda
Kyle
Mike
Ben
Joe
Brent
Lou
And the butler Giles
Basically there's one killer but no one except the killer knows who it is but the killer pretends not to be it and you won't know till the end who it is, watch the show to understand better