In my canon he's childless I think (I haven't totally decided since even if he had a kid they'd have died long ago). In the show his first wife and his daughter died in a car wreck when someone shot the military guard who was driving. He never mentions them until he has no choice because he was so devastated. But he also deals with the son of a missing officer and with a deaf child who had been kidnapped, he's very good with them. He's a total marshmallow on the inside when it comes to kids :D