Hypothetical

I have a hypothetical question for you. Not being a lawyer or a constitutional scholar, you have to excuse my ignorance (but perhaps applaud my curiosity). What would happen if a president of the United States murdered someone and there were multiple witnesses? Let's say it happened on the steps of the White House, the president held a gun to someone's head, pulled the trigger, and shot the person dead, all the while being observed by multiple first hand observers. So could he be arrested for murder? Is there any law or rule that allows for such a president to be exonerated, or at least, allowed to go free pending a hearing or whatever? Or could he just be jailed until such time he was tried for murder? Remember, we are talking about a blatantly obvious cold-blooded murder witnessed by several people where there is no doubt whatsoever about what happened. It would seem to me that such a president could clearly be arrested and charged and even incarcerated while awaiting trial. What do you think?

Now, if you think as I do, that a president caught flagrantly murdering someone ought to be arrested just like any other murderer, what about a president that is known to have murdered thousands of innocent people, including children? Why should he not be arrested and charged with murder, in this case even worse, war crimes? Bush/Cheney are known to have committed multiple war crimes. The fact that they are trying to change the laws retroactively absolving them of responsibility is in itself an admission of guilt. Indeed, the entire world knows they are guilty of war crimes. So why worry about impeachment? Why should they not simply be arrested and charged with crimes everyone knows they committed? They could not, of course, be presumed guilty without a fair trial. So why should they not have a fair trial to determine whether or not the charges of war crimes are valid? Personally, I believe in this particular case impeachment would simply be a waste of time. Either they are guilty of war crimes or they are not. Even if they can succeed in retroactively changing the laws everyone will know they are still guilty. Let them explain in a court of law why they went to "war" in Iraq. Let them explain why they condoned torture, war profiteering, the use of illegal weapons like white phosphorous and cluster bombs, and why innocent civilians, including children, were targeted. I believe these are the kinds of questions that can only be answered by open trials. They cannot be ignored even if our Republican Congress is stupid enough to try to make them retroactively legal. The die is cast. Either these criminals should be held responsible for their murderous acts or they should not. So what do you think?