Announce and act, is kinda foolish act, so the culprits can easily fly away to other countries, and various Big fishes are already outside of the country. I think LEA's should have more than enough evidences and proofs so that they dont require these politicians and Big fishes skirmishes or foolish panic acts... They have to take the action against them if they want to remove this menace once and for all...
Zardari is also involved in various crimes as stated by Dr. Shahid Masood, and Dr. Zulfiqar mirza.. and hence zardari was also linked with Bibi's death.. and even Bilawal bhutto knew that... So have to put hands on them before they left the country again with any kinda deal from this government...