That is a target point. If it had been a broadhead, that hawk would have died quick.
This was an idiot practicing for bow season. Retrieve the arrow and you can tell where it was bought/cut and draw length. And a lot of archers put ‘signature’ fletching on their arrows (specific colors). Should be kind of easy to find a suspect.
With that being a target point, it may not have been “customized”.
Is there a public or private archery range nearby?
It could have been an accidental shot with the hawk swooping down to catch some prey, and caught something else instead.
But if it was intentional, my bet is on some stupid high school kid. And if so, the kid AND the parents should be punished with whatever maximum fines and jail allowed as well as lifetime bans from obtaining hunting licenses.... And the kid should be shot at with an arrow.
“This was an idiot practicing for bow season”....
And you have determined that how? Perhaps it was shot for some other reason. While I don’t condone the shooting, lets not be so hasty to blame a hunter.