To compromise Geary it would seem all they needed to do was to get com photographs of him with the hooker, and some statements that he was a regular there, and into really kinky game playing, and they would have him by the short hairs (especially with the Corleone's people in the press). So why did they have to kill an innocent person to further this agenda? IS this supposed to show how much more brutal Michael was than Vito? After al look at the trouble Clemenza went to just to make sure "pain in the ass innocent bystanders" didn't get hurt.