That is simply not true. While medically assisted death may technically be illegal, it is widely practiced in this country. While you cannot walk into a hospital and ask for help dying, if you are in the hospital and suffering, clearly dying, it is quite common for a doctor to knowingly provide a level of pain relief whose outcome will result in death.
This type of 'specific killing' may not be debated in Congress or on the internet, but in hospital rooms with the family involved it quietly occurs, is accepted, and is, IMHO, the right thing to do.