Is it possible that Hal is the Black Hood, and that he arranged for Chic’s roommate to kill the real Chic and then move in with the family?
That said, if Chic isn’t the real Chic, and if Hal wanted the real Chic out of his life, the imposter took care of things for him.
Riverdale strongly implied Betty’s dad is the true Black Hood in “Prisoners,” and if he is, we can assume he’d stop at nothing to get Chic out of his life permanently.
If Hal Cooper turns out to be the Black Hood, this would complicate this theory.