Or he&#x2F;she was a pro and left the casings and a chunk of the gun on purpose to cast doubt on the idea that he&#x2F;she was a pro.<p>Once you go to the level of &quot;this was state sponsored in some way&quot; all normal investigation and inference goes out the window.  State sponsored folks would know how normal police investigations are conducted and have plenty of ways to counter them.<p>Why a particular state would want these people dead is another matter entirely though.