Depends, are you aksing if you can kill using magic, or if by using magic I could be killed...
I don't see a situation where using magic would kill me. However, some spirits have been known to kill/seriously harm devout workers who attempt to back out of their practice.
Now, to what I assume your actual question is, can you kill with magic? To which I say, absolutely. By way of bringing about serious illness or misfortune through many practices. Many people will say you can't, but why accept their limits as your own? All I can say, is you better have a darn good reason before you do that work.