Is turning off a patient's life support system encouraging to kill? If a person is on a life support system due to the failure of one or more organs and not able to return to normal life without them again, if the family consents to the doctors' recommendation to turn off the artificial life support, can this be considered encouraging to kill, violating the first precept?
No it is not killing. Because there's no intention of killing. You just stopped doing things to sustain his life. It doesn't even have to be a relative. So many people die due to famine all over the world. So many animals are being slaughtered every day. You could stop everything you are doing right now and go and try to save them with all your time and money. But by not doing that, are you killing those whom you might have saved? No! Not doing a good deed isn't necessarily doing a bad deed.

But if there's the intention of killing, turning off the switch breaks the 1st precept.