The police know it best, but this does not sound credible in the face of other media reports circulating regarding militant / terorist activity in India.
It is often claimed that the militants operate on a module / strictly need to know basis, and have no really important info than their objective and possibly, route map. Even that is not clear if media reports are to be believed, saying that they are only told of who they will meet at the end of the journey from place A to place B and that they will receive further (limited) instructions from him, till they reach the next point of their journey. This way, even if captured, they are useless to sleuths as they really don't know much.
Here, they had reached the final point of their journey and were obviously in the suicide attack mode. It therefore seems illogical they would have so much useful info on them. Perhaps the sleuths are put to sniffing the wrong leads, as they just cannot ignore anything and thus waste considerable man hours and energy in verifying useless leads as useless?