Vietnam was the last war with a draft so you had a higher cross section of individuals/geographical areas. From the web:

The states with the most active duty and reserve members of the military, as of May 2016, were:

California: 190,160
Texas: 173,118
North Carolina: 129,049
Virginia: 117,084
Florida: 94,288
Georgia: 88,521
Washington: 65,731
New York: 50,824
South Carolina: 50,426
Hawaii: 49,347
Maryland: 49,187

NJ is even further down the list with 7,000 active military members.

Since there is no draft, you have to enlist to be in the military post-Vietnam. That suggests a certain level of selflessness that most mobsters do not possess.

Of course there are cases where recent military members have committed crimes and they're not all angels. There have been reports of latino/black gangs activity in the US Army that you can read about.