A natural parent generally has a constitutional right to raise his or her children. The right can be limited, of course, as when there is abuse or neglect. However, in Ohio and all other states, the natural parent will have a superior right to legal custody over a stepfather or a grandparent.
Thus, where the children were living with the mother and stepfather, and the mother died, it is unlikely that the stepfather will have a superior right to custody over the natural father. That very issue is playing out in another state right now, and it will be interesting to see whether the court will affirm the general, longstanding rule of superior rights to the father. Apparently, the two teenage children have expressed a wish to remain with the stepfather.