As we all know that every serial of EKTA's is coinciding with another serial. I think KAHIIN TO HOGA is similar to the serial of KAVY ANJALI.
In KAVY ANJALI, HETHIN was madly in love with ANJALI and, ANJALI married KAVIYA. To take revenge, Hethin killed KAVIYA.
In the same way it maybe the same here to in this serial. SUJAL was madly in love with KASHISH, and KASHISH marries MR. ALUWALIA. So out of revenge and anger SUJAL kills MR. ALUWALIA.
In KAVY ANJALI, KAVIYA had divoced his second wife and got back to his first wife ANJALI, but here in KAHIIN TO HOGAA, CHARU refused to give SUJAL the divoce.
In the end, in the serial, SHOAN and ANJALI get together and get married. Because ANJALI loves SHOAN, as SHOAN's face cut looks like KAVIYA, whom ANGELI loved him very much. Here too, KASHISH loves SUJAL verymuch and in the end both will get together and get married.
It maybe or maybe not possible for SUJAL to kill CHARU and MR. ALUWALIA
I dont think that SUJAL will go that far to take anybody's life.
It can also be possible for SUJAL to kill MR. ALUWALIA, because he has many times treathened MR. ALUWALIA that he will kill him so that there will be no any word heard from him.
But if KASHISH says that the killer is from this house (ALUWALIA's house) then I dont think it will be SUJAL. Not even SHIPRA, GAYATRI or KARTICK. But it will be SIDDHARAT.
LET's WAIT AND WATCH.