The U.S. special forces team that hunted down Osama bin Laden was under orders to kill the al Qaeda mastermind, not capture him, a U.S. national security official told Reuters. "This was a kill operation," the official said, making clear there was no desire to try to capture bin Laden alive in Pakistan.
An assassination is "to murder (a usually prominent person) by a sudden and/or secret attack, often for political reasons." An additional definition is "the act of deliberately killing someone especially a public figure, usually for hire or for political reasons."
Assassinations may be prompted by religious, ideological, political, or military motives. Additionally, assassins may be prompted by financial gain, revenge for perceived grievances, a desire to acquire fame or notoriety (that is, a psychological need to garner personal public recognition), a wish to form some kind of "relationship" with the public figure, a wish or at least willingness to be killed or commit suicide in the attack.