All species of Hawks are becoming endangered and are protected by law so if you get caught killing a Hawk without good reason then you can face 6 months in prison and/or a $15,000.00 fine.
However you can get special permits to kill a Hawk if you really need to kill a hawk.
Although Hawks are pretty much endangered the Harris Hawk species is not as endangered as other species of hawks and currently the Harris Hawk is not listed as of yet as being endangered.
All hawks including the Harris Hawk are protected from being harassed or hunted by the Migratory Bird Treaty Act but that doesn't mean that someone won't kill the Hawk anyway and make them endangered in the future or completely wipe them out one day.