Can president of U.S. order a hit on American soil?

In the latest twist in the debate over presidential powers, a Justice Department official suggested that in certain circumstances, the president might have the power to order the killing of terrorist suspects inside the United States. Steven Bradbury, acting head of the department's Office of Legal Counsel, went to a closed-door Senate intelligence committee meeting last week to defend President George W. Bush's surveillance program. During the briefing, said administration and Capitol Hill officials (who declined to be identified because the session was private), California Democratic Sen. Dianne Feinstein asked Bradbury questions about the extent of presidential powers to fight Al Qaeda; could Bush, for instance, order the killing of a Qaeda suspect known to be on U.S. soil? Bradbury replied that he believed Bush could indeed do this, at least in certain circumstances.
I certainly hope this is the case, just like a police officer has the right to neutralize dangerous suspect if the latter represents a threat to people in his surroundings - I wished president had known 9/11 highjackers assassinated prior to attack - oh well, once this will surface in Newsweek magazine this week - libs will berserk AGAIN, world had enough of liberalism.