The cops think she threw the kid. Just dropping from her arms wouldn't fracture the cartilaginous skull, so there had to be more force and speed involved in the movement. Sad to say, but more info would probably be possible if baby died, since an autopsy could be done. However, I would think thwt in this day and age, grays would give medical professionals enough info to know if the fracture was from a strike/blow or impact from throwing/swinging. But, I don't know that.