Kidnapped
Now, this is just wild, how does a kidnapper get custody of the kids that he kidnapped in the first place? It only makes sense if he forged all of their paperwork and changed their names, then possibly he would be able to get around the system, but it would be a stretch.
It would take a criminal of some high talent to be able to pull this off. Just why would he want to kidnap two kids and raise them as his own? Someone, please explain to this man that if it is healthy, he can always just fall in love with a woman and make his own children one day.