Principles of Practice: How to Conduct Proper Investigative Interviews and Interrogations
Principles of Practice: How to Conduct Proper Investigative Interviews and Interrogations Written By: Joseph P. Buckley
Since 1947 John E. Reid and Associates has been conducting investigative interviews and when appropriate, interrogations.
Since the mid 1970's we have been teaching investigators from law enforcement, government agencies and the private sector from around the world proper interview and interrogation procedures. In this document (an expansion of a prior Investigator Tip) we will detail the procedures, guidelines and best practices that we teach to all investigators, and will include references and supporting documentation.
(See the What's New entry dated February 25, 2022 entitled, "Development of the Reid Technique.")
Our purpose is to reinforce the core principles of practice that we feel are essential in conducting effective interviews and interrogations, and are the principles of practice that we teach in all of our training programs.
The Essential Elements of the Investigative Interview
- The initial contact with the subject (absent a life-saving circumstance) should be a non-accusatory, non-confrontational interview. 
- All interviews should be conducted in accordance with the guidelines established by the courts; such as the appropriate advisement of rights; the presence of a parent or guardian for a juvenile; etc.
- Throughout the interview the investigator should maintain a neutral, objective fact-finder demeanor. During the interview the investigator should not engage in any accusatory or confrontational behaviors.
- The interview should begin with casual conversation, biographical information, employment information, etc. to acclimate the subject to the interview process, develop rapport and to develop the subject’s behavioral baseline
- The investigator should use open-ended questions to develop the subject’s statement, story, version of events or explanation of what happened.  In the interview the investigator should do about 20% of the talking and the subject should do about 80%.
- The investigator should observe the subject’s verbal and non-verbal behaviors as a guide for the interview questions – suggesting when the subject may be editing, fabricating or withholding relevant information, suggesting the need for additional follow-up questions It is important to remember that there is no behavior unique to deception – behavior must be evaluated in context and against the subject’s normal behaviors. There are numerous factors that can affect a subject’s behavior during the interview, including culture, mental and psychological impairments, physical condition, drugs and alcohol, etc. which the investigator must consider.
- A subject’s verbal and nonverbal behaviors are not a substitute for evidence, but can be helpful in identifying when a subject may be less than candid during the interview, prompting additional questions which may in turn lead to the discovery of additional incriminating facts or evidence
- The investigator should evaluate the subject’s statement in conjunction with the case facts and evidence. If the subject offers an alibi attempt to verify its authenticity.
- The investigator should not tell the subject what they already know about the case – but rather should see if the subject’s statement is consistent with what is known or if the case facts and evidence contradict what the subject has stated. 
- The investigator should utilize investigative and behavior provoking questions during the interview. 
- The investigator should not reveal all of the details about the crime (it is critical to withhold crime details that can later be used to confirm the authenticity of the subject’s acknowledgment of what he did) 
- Do not show the suspect crime scene photographs that reveal corroborating details
- The investigator should evaluate the subject’s possible involvement in the issue under investigation based on the investigation, case facts, factual evidence and information developed during the interview/investigation
- The interview (and any subsequent interrogation) should be recorded. 
The Essential Elements of the Interrogation Process
- Interrogations should only be conducted when the case investigative information indicates the subject’s probable involvement in the commission of the crime. The purpose of an interrogation is to learn the truth. 
- The investigator should conduct all interrogations in accordance with the guidelines established by the courts - advisement of rights; presence of a parent or guardian for a minor; length of time, etc. 
- The investigator should always treat the subject with dignity and respect
- The investigator should not make any promises of leniency, threats of harm or inevitable consequences, or physically abuse the subject
- The investigator should not conduct interrogations for an excessively lengthy period of time
- The investigator should not deny the subject any of their rights
- The investigator should not deny the subject the opportunity to satisfy their physical needs
- In a non-custodial interrogation do not deprive the subject of the opportunity to leave the room
- The investigator should exercise special cautions when questioning juveniles or individuals with mental or psychological impairments – do not lie to these subjects about evidence 
- The investigator should never manufacture evidence implicating the subject
- When a suspect claims to have little or no memory for the time period when the crime was committed the investigator should not lie to the suspect about incriminating evidence
- The investigator should begin the interrogation with a statement of involvement
- Following this initial statement the investigator should engage in a monologue presentation (theme) in which he/she proposes to the suspect reasons and motives that will serve to psychologically justify or excuse their behavior – not legally justify or excuse their behavior 
- The investigator should attempt to place the blame for what the suspect did on some person or set of circumstances other than the suspect himself and build the subject up as “a good, honest hard-working person who made a mistake in judgment due to …” 
- The investigator should focus the theme on why the suspect committed the act, not if
- The investigator should use an alternative question to develop the subject’s initial acknowledgement of what they did: “Was this the first time you did something like this or has it happened many times before?”
- When the subject acknowledges what they did, the investigator should ask open-ended questions to develop corroborating information – the location of the murder weapon or bloody clothes; how the subject gained entry into the building; where the subject sold the stolen jewelry, etc. Corroboration is an essential element to establish the authenticity of the subject’s statement.
- The interrogation should be recorded. 
- The subject’s confession is not the end of the investigation…the investigator should continue to develop additional details about the subject’s behavior before and after the commission of the crime and to verify the details of his statement of involvement
False Confession Issues