I've used the following link (only 3 pages)
http://academic.mu.edu/phil/jonesj/courses/p10420053rightsnotes.pdfThis link was an effect of searching for Rights Based Ethics on Yahoo...
As to the euthanasia, the proper category for it seems to be the positive natural right. It means, that suffering of somebody entitle me to act. The similar example is to provide food to starving person. Sometimes the aspect of rational mind is not involved, i. e. I exclude the rationality like criterion for having a property (the person is in a coma). But it involves a conflict, because euthanasia is violating the natural right to live, contrary to providing food to starving. What is the reason for reduce somebody on his right to live due to his suffering? It seems, that the chosen category was wrong. The correct category of right to euthanasia is conventional right, i. e. the one, which is imposed by society and here emerges again a question, if it is negative or positive conventional right. That is - does euthanasia interfere with conventional right of someone else or not? In Switzerland it principally doesn't.
Capital punishment can be supposed as conventional negative right in certain countries. Sorry, it should be rather conventional positive right of the majority to be saved from certain danger, because killing of somebody is in conflict with his natural positive rights (i. e. moral rights, which should have precedence before conventional rights).
However there is a principle, that natural (moral) rights should substitute the conventional rights in the cases, when there is absence of them for some reason. Here is incorporated the principle of soul, according to it euthanasia in the case of person in coma is not possible. What about, when the person alone ask for it? That is probably the case of conventional positive right (Switzerland).
Similarly abortion is not possible, when we ascribe a soul to the embryo. And we must consider the fact, that even the conventional positive right is excluded in this case. From this point of view abortion is really close to murder.
You will need to put my answer in order and perhaps make some additions to it. I am sorry, it was only an attempt...