History of criminal investigations and the role of eyewitness testimony

Criminal Investigations

History of criminal investigations

The first "detective force" dates back to 1750, when a small group of community members called the "Take Thieves" banded together and rushed to crime scenes to investigate (Swanson, 2003). This group, spearheaded by Henry Fielding, eventually led to the founding of a police force in London (Swanson, 2003). The next famous "father of criminal investigation" is Robert Peel, who authored the twelve "Peel's Principles," outlining proper ethics for policemen and bureaus, from how to conduct oneself to where to build a police station (Swanson, 2003). Many of his ideas are still in use today. Despite Peel's efforts, corruption was rampant in the first metropolitan police departments, and failures to communicate between jurisdictions allowed suspects to escape (Swanson, 2003). Ultimately, these problems led to detective work being outsourced to private organizations such as Pinkerton's (Swanson, 2003). Pinkerton's detective agency was famous for protecting President Lincoln and creating thorough criminal records (Swanson, 2003).

On a federal scale, the first Secret Service agency was founded in 1865 to fight counterfeiting, but after President McKinley's assassination this group became responsible for "presidential protection" as well (Swanson, 2003). The Bureau of Investigation was established in 1908, and became the FBI under President Hoover in 1924 (Swanson, 2003).

Methods of criminal identification first evolved from anthropometry, or the measurement of body parts; this system was used until the development of dactylography, or fingerprint identification (Swanson, 2003). Dactylography was easier and more accurate, and was widely adopted in the early 1900s (Swanson, 2003). From there, the most significant modern advancement in criminal identification has been DNA mapping (first used in a case in 1986) (Swanson, 2003).

Role of eyewitnesses in criminal investigations

Eyewitnesses play a critical role in any investigation, from traffic accidents to murders. Many people assume that eyewitness testimony is highly trustworthy; however, human beings are swayed by emotion and faulty recollection, so investigators must be careful.

In the courtroom, eyewitness testimony generally incites emotion from jurors, and is therefore a powerful tool for prosecutors and defense attorneys alike. Masterful cross-examination can unmask a liar, just as the right line of questioning can bring out the truth and sway jurors. In addition, eyewitnesses rehearse with their lawyers and sometimes even mock jurors, in order to anticipate cross-examination questions and prevent any surprise attacks.

As a result of the critical importance of eyewitnesses in criminal investigations, the National Institute of Justice created the Technical Working Group for Eyewitness Evidence (TWGEYEE) project in 1998, with the goal of improving the "accuracy, reliability, and availability of information obtained from eyewitnesses" (Dept of Justice Technical Working Group, 2003). The group consists of criminal investigators, lawyers, researchers, and psychologists (Dept of Justice Technical Working Group, 2003). The TWGEYEE has published a comprehensive booklet on their findings called "Eyewitness Evidence: A Guide for Law Enforcement" (Dept of Justice Technical Working Group, 2003).

Types of eyewitnesses

Eyewitnesses can be primary or secondary. A primary witness is the most reliable, having actually seen the crime take place firsthand. On the other hand, secondary witnesses are "hearsay" witnesses, who were not present at the scene but have inside information gleaned from firsthand witnesses. Although secondhand witness testimony is not given the same value as firsthand, it is important to remember that either one can be unreliable. In addition, secondary eyewitness testimony can be tested against firsthand testimony to weed out inconsistencies and zero in on weaknesses.

Other types of witnesses in general include: adverse or hostile witnesses (may be highly prejudiced against one side); character witnesses (testify regarding reputation of defendants and other witnesses); expert witnesses (provide scientific, factual background information to support one side of a case); police witnesses; lay witnesses (not experts); and material witnesses (called to testify on a matter closely related to the case at hand) (Swanson, 2003).

Police interviewing and interrogation techniques

Over the years, law enforcement officials have developed techniques for effective interviewing and interrogation based on past experience, research, and psychology. The ultimate goal of any interrogation is to garner a confession; a confession can save an enormous amount of time and money for everyone involved. Therefore, the term "interrogation" has come to have negative connotations as a result of the sometimes harsh methods used to elicit confessions (Boetig & Bellmer, 2008).

Techniques employed to improve the interrogation process and help elicit a valid confession include: reading and understanding a suspect's behavior when under questioning (i.e., does he have a "tic" when he lies?); making sure "hunches" align with facts; protecting vulnerable individuals (young, mentally handicapped) from making a coerced confession under pressure; performing background research and preparing in advance; asking open-ended rather than "leading" questions; and using psychological "tricks" to make the suspect feel more open to a confession ("rationalization, projection, and minimization") (Napier & Adams, 2010).