Requirements for Being a Criminal Investigator

Criminal investigators must carry and periodically qualify with firearms.
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A criminal investigator or CI is a federal, state or local law enforcement officer responsible for investigating crime scenes, gathering evidence, interviewing witnesses and suspects and providing court testimonies, among other items. Federal agencies, as well as state and local police departments, actively recruit interested candidates whose backgrounds qualify them for investigative work. To become a certified criminal investigator, you must meet certain agency or department requirements. Criminal investigator requirements are basically similar among federal, state and local departments, save for certain unique mission characteristics.

U.S. Citizenship and Residency

Due to the sensitive nature of criminal investigative work, federal, state and local law enforcement agencies require candidates to hold U.S. citizenship. Upon applying, you must provide proof of U.S. citizenship, such as your birth certificate, passport or naturalization papers. You must also have either resided in the United States for at least three out of the past five years or served overseas on military or government duty. Being a dependent of an overseas federal of military service member also satisfies the residency requirement. State and local police departments may also have varying state residency requirements.


To become a federal criminal investigator, you must be between the ages of 21 and 37. You must apply by the last day before your 37th birthday. However, if you have prior military, federal service or law enforcement experience, the age restrictions may be modified or waived. Some state and local police departments have no maximum age requirements, however, candidates under 35 are often preferred.

Driving Privileges

Since criminal investigative work involves a lot of driving, sometimes in risky and compromising situations, you must hold a valid driver's license with a solid driving record. As you will be expected to operate department vehicles, you will need to verify and maintain good driving habits prior to and during your employment as a criminal investigator.


As you will need to gain sufficient clearance to access and handle evidence and other sensitive materials, you will need to undergo a full-scale background investigation. You must possess a passable background, free of criminal or felony convictions, misdemeanors involving domestic violence, drug or alcohol abuse or significant financial mishaps, such as a bankruptcy or government loan default. You will need to successfully pass a polygraph examination to confirm the validity of information you supplied.

Education and Training

Although some state and local law enforcement agencies only require a high school diploma for criminal investigative positions, most federal agencies require a minimum of a bachelor's degree. You will also need to complete the Criminal Investigative Training Program at the Federal Law Enforcement Training Center or FLETC. This basic training program involves 56 days to 22 weeks of comprehensive instruction on investigative techniques and principles, surveillance, arrests, firearm operations, defensive driving and physical fitness.

Mission Mobility

To be an effective criminal investigator, you must be willing and able to respond at a moment's notice to a crime scene within your jurisdiction, regardless of employing department. If you seek federal criminal investigative work, you will need to accept any location assigned by the agency for the first three years. After the initial three years, you may be transferred to other locations depending on agency needs and objectives. You must be ready to accept reassignment to another duty station at any time at the agency's discretion. State or local criminal investigator positions may be more suitable if you want to remain in a particular locale for the duration.

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