Yeah, using magic in any form to kill is A Bad Thing. Mind you, using it to misdirect, distort, warp or misinform or mislead is perfectly okay. Which is why I have no problem making a construct for my wizard, filling it with nitroglycerin, then possessing it after putting my features on it to take to a drug deal or the like is perfectly okay. If the other guy chooses to exercise Free Will and shoot at me, too bad for him. Mind you, I make sure there aren't any innocents nearby and I make sure it takes place at night so my spirit won't be fried by the sun, but it's perfectly 1st Law legal.
Come to think of it, speaking of ways around the laws, pretty sure it's okay for vanilla mortals to research information of the Outsiders without violating the 7th Law.