The classification for inmate custody level is done in Beaumont TX by an arbitrary committee that looks at only hard data. This is not a punitive selection, it is based on several factors that are not made known to the public. If they have him in high security, they must have something more than you have heard. You would not be entitled to reviewing his file, nor could you get any information by calling them and asking. The best your son can do is get into the BOP's recommended programming and work like a good soldier for the next 6-9 months, keep his nose clean and then apply for a transfer. If he has been an excellent inmate, they will start working him down in custody levels until eventually he is home with you.