Army MOS · Support

31D CID Special Agent

Current service use not established

This code is listed in the directory. Inclusion alone does not confirm current service use.

Overview

A CID Special Agent conducts investigations into incidents, offenses, and allegations of criminal activity. They investigate matters affecting Department of the Army or Department of Defense personnel, property, facilities, and activities and may supervise these investigations.

Minimum clearance: Top Secret

Minimum ASVAB: GT 110

ASVAB policy: Not policy-reviewed · coverage unknown · as of 2026-10-19

Program scope has not been reviewed.

Policy applicability and coverage of the program's score routes have not been reviewed. Shown-route arithmetic is not an eligibility decision.

Source: smartbook-611-21-ch10c-fy2025 (source date 2025-12). Policy applicability has not been established.

See if you would hit this score: free ASVAB practice test

Core Skills

  • Criminal investigations involving military personnel and property

Civilian Career Paths

Career associations are editorial assessments of the cited evidence, not an official crosswalk unless the evidence explicitly says so. O*NET supplies civilian occupation information, not proof of a military match. Related experience does not confer civilian qualifications. Tasks and tools below describe civilian work, not military training.

Detectives and Criminal Investigators

Conducting or supervising investigations of criminal allegations affecting Army or DOD personnel, property, facilities, or activities directly overlaps with civilian criminal investigation work.

How to prepare: Ask a target agency to assess your CID experience for its appointment route, and plan for the academy and supervised on-the-job training most police and detectives must complete. Applicants need at least a high school diploma or equivalent, while some agencies require college coursework or a degree.

What the civilian work involves
  • Obtain facts or statements from complainants, witnesses, and accused persons and record interviews, using recording device.
  • Record progress of investigation, maintain informational files on suspects, and submit reports to commanding officer or magistrate to authorize warrants.
  • Prepare charges or responses to charges, or information for court cases, according to formalized procedures.
Civilian tools and software (examples)
  • Microsoft Office software

Notes & Sources

  • Police and detective candidates usually must be at least 21 and meet rigorous physical and personal qualifications; agency requirements vary.
  • Federal officers must be U.S. citizens. Most state and local jurisdictions also require citizenship, but some do not.
Evidence for this guidance (3 documents)
  1. Army COOL MOC feed: 31D CID Special Agent

    [1] data/authority/army-codes.json entry 31D (OSD COOL feed, fetched 2026-07-25); DB rank enlisted, authority codeType enlisted

    Supports: Criminal investigations involving military personnel and property, Detectives and Criminal Investigators (O*NET 33-3021.00)

  2. O*NET: Detectives and Criminal Investigators

    [2] O*NET 30.3 occupational data

    Supports: Detectives and Criminal Investigators (O*NET 33-3021.00)

  3. Bureau of Labor Statistics: Police and Detectives

    [3] How to Become, Education, Training and Other Experience; checked September 24, 2026

    Supports: Detectives and Criminal Investigators (O*NET 33-3021.00)

Defense contractor jobs for 31D

Predecessor codes

Historical codes with documented links to 31D. Each history page explains the change.

Descriptions may be summarized for clarity. Verify all information with your branch career counselor or official military documentation before making career decisions.

Report an error on this page