If the players discover information leading them to the bomber they will not actually find him. He's busy planting the bombs. They are being place around the Council of Worlds complex but at targets with low security priorities (meaning that it was easy to get to these targets but that blowing them up will not actually come close to harming anyone at the Council of Worlds. They are timed to trigger a security reaction that will wisk the CoW delegates to waiting vehicles to wisk them away.
This wisking of the politicians away is what the assassin is waiting for and he'll take his shot as his target is getting into an air car. No one else knows this but the Zenk assassin.
The PCs may discover the bomb locations in an encrypted file on the personal computer terminal at the bomber's apartment (presuming they gain that address from Shin Sting). The personal computer is a level one computer with the following level 1 programs: computer security, information storage and entertainment. They encrypted file is in his photo album under the folder: Vacation Photos. Characters with computer skill that are looking for something may discover this with a LOG check to notice that the file takes up an inordinate ammount of memory. Each picture is an innoccent looking picture of the outside of a location to be bombed. A defeat security roll must be made to decrypt each photograph (3 in all) to see the encrypted files hidden within or "behind" the photos. The encrypted files show floor plans and where to hide the bombs.