if you see the 26 sep episode carefully where ranjeet says that he did not kill the beggar(the wittness) and it could be someone else for whom this witness was a threat.... and we all well know that ranjeet is working for bawa, so if he or bawa murdered kunal he would have never said all that and made the shekhawats belive that its not akash but someone else behind the murder of kunal....
and after this i guess theres only dev left as a suspect!!
and i fell this could be true becasue as in anurag basu movies(murder, gangster) the best trusted person was the evil one.... and so he might use the same concept here......
well this is just my opinion..... though i wish i be wrong!!!!