Hey everyone please answer this?

ok I know this is impossible but lets say that the same thing happened to obama that happened to the president in the gi joe movie if I had proof that it was true and was a former black ops trooper or something and if I kill the entire secret service and snipers regiment and the cops protecting the fake president on national television then prove that the president is not really the president and then shot the impostor should I be prosecuted I don't think so since technically I am saving the US and those deaths were a necessary sacrifice