Section 6: Information From People

Fundamentals of Criminal Investigation by Adam J. McKee

While forensic evidence is extremely valuable, most cases are ultimately resolved because of information that comes from a person who saw the crime happen, who was the victim of the crime, or who perpetrated the crime.   This evidence, which is testimonial in nature, comes from people.  It is important to realize that people make mistakes and can be led by suggestive interview techniques.  Well-meaning witnesses can identify the wrong person; they may fail to identify the perpetrator.

The investigator must not only obtain the desired information but must obtain reliable information that can be used in court.  The courts, recognizing this potential for human error, have instituted legal policies that dictate how police obtain information.  In addition to mistakes made by witnesses, the law protects the civil rights of suspects by dictating how interviews and interrogations must be conducted.  Ensuring these rights is a major component of the investigator’s job when trying to obtain information from people.

Initial Report of a Crime

Nearly every crime begins with a call to the police.  These calls are most often routed through the 911 system where a dispatcher takes the call.  This is where the information gathering process begins, and dispatchers need to be trained to get it right.   The dispatcher is usually the first point of contact with a witness, be they an eyewitness or a victim (or sometimes even the perpetrator).  The call-taker should seek to obtain complete and accurate information in a nonsuggestive manner, and then relay that information to officers in the field.  This information may include the identity and description of the perpetrator. The actions of the dispatcher can impact the safety of everyone involved in the investigation, as well as impact the overall success of the investigation.

The first order of business is to deal with the exigency of the call, assuring the caller that assistance is on the way.  People who call 911 do so because they want help, and they are not likely to calm down and be cooperative if they are not assured that help is coming.  Following this, the dispatcher should as open-ended questions. If these open-ended questions leave out important information, then it is appropriate to ask closed-ended, specific questions.  The dispatcher must avoid asking suggestive or leading questions. (e.g., “Was the vehicle a red F150 pickup?”). The dispatcher should follow up by asking if there is anything else that should be known about the incident.  Pertinent information should be immediately transmitted to officers in the field, and officers should be updated as more information becomes available.

Preliminary Investigation

In these days of the CSI Effect, the importance of physical evidence and forensic analysis are at the forefront of the public’s imagination, and these effects can rub off on police officers as well.  It must be remembered that most crimes are “cracked” by information gathered from people. More often than not, it is “good old fashion” police work that solves cases, not the mere presence of physical evidence.  The preliminary investigator’s job includes obtaining, preserving, and maximizing the amount of accurate information from the crime scene.

An obvious first step is to try and identify the perpetrator, and, if they are still present at the scene, detain or arrest them.  The next step is to determine if a crime has occurred, and, if so, classify it. As soon as new information becomes available, undated descriptions of the incident, perpetrators, and any involved vehicles should be broadcasted to fellow officers.  

The identity of witnesses should be verified.  Witnesses should be separated and instructed not to discuss the details of the incident with each other.  The area should be canvassed for other witnesses.

The manner in which the preliminary investigating officer obtains information from witnesses has a direct impact on the amount of accuracy of that information.  Such information forms the foundation of subsequent follow-up investigations, and thus should not be taken lightly.

A first step in any attempt to obtain information from any person is to establish a rapport.  A first question should always be concerning the condition of the person. If they are healthy enough to continue the conversation, the officer should begin with open-ended questions and augment those with closed-ended questions.  As always, the use of leading questions should be avoided. Any vague or confusing responses should be clarified. All information obtained from witnesses should be preserved in a written report, always including the identity of the witness.  Witnesses should also be encouraged to contact investigators with any further information. Many investigators carry business cards with their contact information on them for this purpose. Witnesses should be encouraged to avoid media exposure to media accounts of the incident.  They should also be asked not to discuss the details of the incident with other potential witnesses.

Modification History

File Created:  05/02/2019

Last Modified:  02/03/2024

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