At the time, the Army needed to fill their recruiting quotas and apparently was issuing waivers for people like this.
It was like that back in the 70's too. I finally discharged a thug who was a barracks thief and discipline problem. Come to find out he had a long juvenile record with serious crimes, but the recruiter took him anyway.
I recall a ‘bad” kid in my high school class was given a choice; The Iowa Reformatory at Anamosa or a free bus trip to Fort Leonard Wood.