Military Police
Career Management Field 31 covers every Army law enforcement function, from writing traffic citations on a stateside post to running a war zone detainee facility. The mission connecting every CMF 31 soldier is the same: protect people, enforce the law, and maintain order so the rest of the Army can do its job.
Four MOSs make up the field. Three of them require a Secret clearance before you ship to training. All four train at Fort Leonard Wood, Missouri, home to the U.S. Army Military Police School. The work looks different in each role, but the underlying skill set, disciplined judgment under pressure, clear communication, and willingness to confront difficult situations, runs through all of them.
Law enforcement experience from the military carries genuine weight in the civilian job market. Police departments, federal agencies, and corrections systems all recruit from CMF 31. If you want a direct, paid path into a law enforcement career without spending four years on a criminal justice degree first, this career field delivers that.
At a Glance
| MOS | Title | ASVAB Area | Training Length | Civilian Equivalent | Clearance |
|---|---|---|---|---|---|
| 31B | Military Police | ST 91 | ~20 wks OSUT | Police Officer | Secret |
| 31D | Criminal Investigation Special Agent | ST 107, GT 110 | 15 wks CIDSAC (plus ~20 wks OSUT for direct accessions) | Criminal Investigator | Top Secret |
| 31E | Internment/Resettlement Specialist | ST 95 | 8 wks AIT | Correctional Officer | Secret |
| 31K | Military Working Dog Handler | ST 91 | ~28 wks total (BCT + AIT + MWD course at Lackland) | Law Enforcement K-9 Handler | Secret |
Which Role Fits You?
The four MOSs in CMF 31 feel nothing alike day to day, even though they share the same career field number. Matching yourself to the right one early saves you from reclassifying two years in.
If you want street-level law enforcement work, 31B Military Police is the core job. You patrol post, respond to calls, investigate crimes, and run detainee operations when deployed. No other MOS in the field gives you that mix of daily hands-on police work with a firearm on your hip. It’s the broadest assignment in the field, and it feeds into all the specialized roles below. Many 31D agents and 31K handlers started as 31B MPs.
If your interest is investigation rather than patrol, 31D Criminal Investigation Special Agent takes you in a completely different direction. You work felony-level cases independently, wear civilian clothes, and carry the same federal law enforcement credentials as FBI and DEA agents. It’s not an entry-level MOS; you either reclassify from another role after reaching E-4 or enter through a direct accessions program for college graduates. The ASVAB bar is the highest in the field (GT 110 and ST 107), and the clearance requirement jumps to Top Secret. If you’re drawn to detective work and analytical thinking over patrol and physical enforcement, 31D is the right target.
If you prefer a structured, facility-based environment, 31E Internment/Resettlement Specialist focuses on the custody and management of prisoners and detainees. Most of your career happens inside a controlled facility rather than on patrol routes or in the field. The schedule is predictable, the skill set transfers directly to civilian corrections, and the ASVAB threshold (ST 95) sits between the 31B and 31D requirements. Soldiers who value routine and indoor work, and who want a career pipeline into federal or state corrections, fit this role well.
If you want something genuinely different, 31K Military Working Dog Handler pairs you with a canine partner for patrol, explosive detection, and building searches. The training pipeline is the longest in the field at roughly 28 weeks, including a specialized course at Lackland AFB in San Antonio. The physical demands are constant, there are far fewer positions than 31B, and promotion slots thin out above E-6. But if working with dogs is something you actually want to do, no civilian job gets you there with the same speed or funding.
The comparison table above covers ASVAB scores, training length, and clearance requirements side by side.
Common Entry Requirements
All CMF 31 roles require U.S. citizenship, a high school diploma or GED, and a minimum AFQT score of 31 (diploma) or 50 (GED). Every MOS in the field requires at least a Secret security clearance, which means a background investigation covering criminal history, finances, and personal conduct. Initial training for all four roles runs through Fort Leonard Wood, Missouri. Soldiers with felony convictions, significant drug history, or major financial problems will face clearance obstacles across the entire field. See each role’s profile below for specific ASVAB scores, training details, and additional requirements.
Career Field Directory
- 31B Military Police: patrol, traffic enforcement, crime scene response, and combat support; the broadest law enforcement role in the field
- 31D Criminal Investigation Special Agent: independent felony investigations under federal law enforcement authority, carrying the same 1811 credential as FBI and DEA agents
- 31E Internment/Resettlement Specialist: custody and management of military prisoners and enemy detainees inside controlled confinement facilities
- 31K Military Working Dog Handler: trains and deploys with a canine partner for explosive detection, building searches, and installation security
Related Resources
Explore all Army enlisted career paths to compare CMF 31 against other career fields. Every CMF 31 role requires competitive ASVAB line scores, so preparing early matters; our ASVAB study guide covers the ST and GT composites you need to hit, and if you prefer to test from home before MEPS, the PiCAT is a verified remote option.