By Dr. Jarrod Sadulski  |  02/05/2024

how to become a criminal interrogator


Criminal investigators – such as detectives, police officers, or other law enforcement officials – work to solve crimes at the local, state, or federal level.

Criminal investigators receive training, often through continuing education at a police academy or through a specialized training program offered somewhere else. Police departments depend on criminal investigators to have strong investigative and interviewing skills, which enable them to solve crimes.


Learning How to Become an Interrogator Starts with Acquiring Communication Skills

A common role for a criminal investigator includes conducting interviews with victims or witnesses and interrogating suspects, so it is critical to develop good communication skills.

In the course of my career, I have conducted many interrogations of suspects. I even conducted the interrogation of a domestic terrorist who was planning an attack on a critical infrastructure in Miami shortly after 9/11.

But earlier in my career, I had to learn to listen carefully for any inconsistencies when I was first learning how to properly interrogate suspects. I also learned to phrase questions carefully and watch a suspect’s body language.


Criminal Investigator Roles

If you want to become an interrogator, it’s necessary to understand criminal investigator roles. Criminal investigators' work involves a number of disciplines, a lot of training, and specific degrees.

Criminal investigators must examine crime scenes to uncover evidence for an in-depth investigation. They must also know the basics of forensic science and know how to submit evidence to a crime laboratory.

Typically, criminal investigators have at least a high school diploma and an associate or bachelor's degree. He or she is usually a graduate of a police academy and has experience as a patrol officer. Aspiring investigators should also have a solid understanding of criminal law and criminal justice.


Common Tactics Used in Interrogations by Criminal Investigators

Effective interrogators begin with preparation. Criminal investigators will typically interview witnesses, collect as much evidence as possible from the crime scene, and gain as much knowledge about the case before beginning to talk with a suspect.

This preparation is useful because it helps criminal investigators to detect deception in suspects. At the beginning of a talk with a suspect, it is common for a criminal investigator to ask baseline questions to which the investigator already knows the answers. These questions might involve information from the crime scene or from eyewitnesses.

With preparation, the criminal investigator may be able to gauge the integrity of the suspect during an investigation. It can also help to identify conflicting accounts later.

Another tactic used by criminal investigators in an investigation is the friendly approach. The suspect will receive an offer of food or drink, and the investigator will work to develop a rapport with the suspect to encourage him or her to talk.

The investigator must quickly determine if the suspect has the mental faculties to be interrogated and if that suspect is under the influence of alcohol or drugs. A confession by someone under the influence of drugs or alcohol will likely present later problems during a court case.

A criminal investigator may also tell suspects that whatever crime for which they are accused is not as bad as another crime. For example, a criminal investigator looking into an armed robbery may infer to the suspect that the charges are not as serious as other criminal charges, such as murder. This method of building rapport is a tactic that encourages a suspect to talk more about the crime that suspect may have committed.

Also, a criminal investigator monitors a suspect for voice inflection, eye contact, and body movements after each question. This monitoring is useful because it can indicate deception or guilt that requires the interrogator further questions.

A good criminal investigator can tell when a suspect is truthful. From my experience, asking open-ended questions, monitoring a suspect for conflicting accounts of the same incident, and displaying the available evidence to the suspect can be effective in obtaining a confession.

You might think that empathy from investigators would be out of place in such a situation, but that’s not true. Empathy for the suspect is effective in some cases.

For example, I have investigated robberies that were committed because the suspect needed food for a child. While this need for food does not make a robbery less of a crime, it does present the opportunity for criminal investigators to display empathy toward the suspect by using a softer tone.

In other cases, empathy is a powerful tool in building rapport. Empathy can result in the suspect displaying remorse toward a victim and motivating that suspect to provide a more accurate account of the crime.

Another common tactic used by investigators is to ask the same question in different ways to determine if the suspect provides a consistent response. When the suspect provides conflicting answers to the same question, the criminal investigator can point out the discrepancy to the suspect and encourage the suspect to be truthful.

In some interrogations, the suspect attempts to control the discussion. They may answer certain questions but refuse to answer other questions, becoming hostile.

In this case, criminal investigators should apply emotional intelligence; getting angry or aggressive does not result in success. Instead, criminal investigators need to remain calm and try a different approach. Ideally, an effective interrogation ends with a suspect’s confession.


Steps for Aspiring Criminal Investigators

Aspiring criminal investigators must meet certain education requirements of potential employers, such as earning a GED certificate, a high school diploma or a college degree. Candidates must also pass a background check, prove that they have acquired certain skills, and take written tests. It typically takes a significant amount of time to go through the hiring process at either the federal or local level.

Applicants typically complete basic training involving physical fitness tests and other tests at a police academy. After basic training, they might then gain experience as a police officer or work in related careers, such as a law enforcement position for a federal government agency. Many police force employers utilize an interrogator who is also a detective.

For law enforcement officers, a police department may have educational requirements, such as a bachelor’s degree, to be a criminal investigator. Many employers of criminal investigators may require a candidate to have at least two years of road patrol experience; other candidates might need at least five years of experience in law enforcement.

Patrol experience helps to prepares a police officer to pursue a career as a criminal investigator, thanks to the knowledge gained by responding to criminal activity and interacting with suspected criminals. For instance, police officers on road patrol learn to conduct field investigations, which can be useful knowledge later in a career.

Officers interested in investigations, interrogation, and criminal investigator positions may wish to pursue specialized training and education to prepare for this type of career. Fortunately, there are many excellent opportunities in law enforcement, from local police departments to federal agencies, where investigators can be useful.


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About the Author
Dr. Jarrod Sadulski

Dr. Sadulski is an Associate Professor within our School of Security and Global Studies. He has over two decades in the field of criminal justice. His expertise includes training on countering human trafficking, maritime security, effective stress management in policing and narcotics trafficking trends in Latin America. Jarrod frequently conducts in-country research and consultant work in Central and South America on human trafficking and current trends in narcotics trafficking. He also has a background in business development. Jarrod can be reached through his website at for more information.

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