If you suppose that you are nothing more than the molecules that make you up, then the only thing you can own are molecules. However that poses a problem since our bodies are constantly changing out molecules. In fact, 98% of the molecules in our bodies are replaced yearly.
There is not a core of molecules that persists, so the best we can say is that we are only leasing the molecules of our physical bodies. So when we talk about moral obligation, it seems dubious to center it on a physical object since that object does not persist. The molecules that made up Jeffery Dahmer when he killed all his victims did not make him up 2 years hence, so should we have released him since his “bad” molecules were now dissipated?