Dirty Bird,
One of the things I haven't seen posted in the recommendation for federal employment is that many of the positions: A) require a degree and/or B) are only open to Veterans.
Without a DD-214 in hand (or prior federal service) there are many federal LE jobs in which your son won't even be referred for an interview and subsequently will never be considered.
Further, without prior local (city, county, or state) LE certification and experience, he may not be referred for an interview and subsequently will never be considered.
In my case (2014-2016), I had a decent resume, basic peace officer certification, experience, education, deployments, Veteran's Preferences, and DD-214 in my favor... even with all those I was still non-referred on most federal LE positions.
Like several posters above I would seriously consider the options of: A) a career far from LE, B) a start with a COMMISSIONED position in the military, C) a career with a local, southern, and red community sheriff's office, or D) go military reserve with commission and local sheriff's office.