Let's see that policy.
The camps were created by political leaders in Germany and sustained by the Nazi party.
That made them legal, at least, at that time, in Germany.
Again, let's see that policy.
Oh and if it was perfectly legal why were so many people that were involved convicted of war crimes?
In Germany it was legal. State policy, there were various laws to send them and kill them in the camps.
Deportation orders, denaturalization orders.
Laws to prevent people with disabilities from having kids, then sent to camps.
Nuremberg Laws