Why would anyone want to transfer their grief over their son's tragic murder into a misguided political campaign? The father here needs to avoid trying to quell his emotions by seeking revenge against innocent people who had nothing to do with his son's murder.
Calling this "internal terrorism" is just sad.
I can understand a parent emotionally reacting over a child being murdered, as I am sure most of us can. If he is doing this alone, then he needs counseling. He made need counseling even if he is not. It is far more likely that he is being exploited by others for political/personal gain. Those using this man and his son's murder to pursue a campaign based on bigotry and racism possess no sense of decency, honor, or sense of respect for humanity.