If one were to buy into conspiracy theories, one would have to believe that such an illegal assassination would take the form of Vince Foster showing up in Fort Marcy Park - not a guided missile landing in a restaurant at lunch hour.
On the other hand it would be hard to assassinate a large group of people in the same manner, it would have to be more dramatic, say like the massacre at Waco but much safer for the police.
This is very different from a Hellfire missile fired from a drone into a Boston cafe at lunch hour. There is no way the public would believe for a second - especially in this age of ubiquitous social media - that everyone in a public thoroughfare happened to be a wanted terrorist.