The grisly murder of Ahmed Rajib Haider is a heinous crime that deserves swift investigation, prosecution, and punishment. The Bangladeshi state has impressive technological resources at its command for keeping track of its citizens and their means of communication. There should be no lack of political will to investigate this murder.
Given the confluence of these factors, I hope that the police/CID/RAB will be able to come up with credible suspect information soon (which they have not done so far at the time of this writing).
The dead are now beyond all our cares and sorrows. It is now up to us, the living, to give the best meaning to their death.