[IYAS9YAS]

A 25-year-old who served four years overseas as an officer and was discharged at least a year ago? That would mean he was commissioned at 19 or 20. NFW.

I Googled the term Assistant Training Officer Instructor and found this: http://www.famu.edu/cesta/main/index.cfm/naval-sciences/staff-biographies/assistant-marine-officer-instructor/. This article shows the "officer" in question to be a Marine Gunnery Sergeant. So, likely an enlisted position, rather than commissioned.

[IYAS9YAS]

That term I got from the NY Daily News article here after Googling his name for other articles. I then searched on Assistant Training Officer and found the Gunnery Sergeant. Appears to be a Drill Instructor, maybe?