This kinda reminds me of a detective conan ep, they have a house full of "suspicious" people and everyone is trying to either hide their own petty crimes or stay silent in hopes that the killer will help them get all the inheritance. all the while the killer roams free because no one is actually trying to find them. and by no one I mean the cops...
I get when sometimes the main character needs to find the killer becasue the cops are incompetent, but here they just took out the cops becasue they want the household members to do the investigation alone ;/ the cops barely visited the crime scene ;/

they are only limited to the mansion set and they rarely go out so it is way too limited and the number of eps are short but still too long for this kind of setting and plot.

tbh if you take out all the petty suspects it's pretty clear who the killer is and it's funny when two 20 year old girls are the only ones doing the research. also isn't it illegal to release the circumstances of an ongoing crime to the public and let them help with the investigation?

anyway, again with the ep count it's obvious they knew they can't drag it for 16 or even 12 eps, but tbh they only needed 2