Did he have custody of the kids or was he allowed to see them? If not, then he was attempting to kidnap them.
Aren't you making an assumption that he is the 'father' of those children ? The AP says, "black father...." and leaves it to us to assume the rest. He could be the father of 10 other children, and not the ones in the car. For all we know, they weren't his and the police thought he might injure them if he got in the car. In his condition, who on earth would trust that he wouldn't ?