JMO but I do not believe DS was the bio father of Hailey. Just doesn't make any sense to me he would murder her under any circumstance, if he really and truly loved her and thus the reasoning behind abducting her. I know some young people do stupid things, but if he thought he was the bio father and wanted custody or visitation rights, why not file it in court and get DNA testing done settling it like a normal human being. Obviously there was something abnormal about him, but there's no justifiable reason, going to great lengths to abduct and then turn around and murder that child IF he thought she was his. Shows no love whatsoever and why would he go to great lengths of bother to abduct her unless it was done out of love.
Now on the other hand, if he was threatened with paternity testing and threatened with having to pay child support, that may be a different story. Still no right to murder an innocent child. And if that was the case, why not go through the court/DNA process, wait until the truth came out before doing something so evil. Personally I'm not buying the speculation DS was Hailey's bio father but that's JMO.