I love it when I have a class and there are detectives and officers with 20 or 30 years or more of experience in there as students. It really demonstrates their desire for additional knowledge and their understanding of the value to be a lifelong learner. Over the years I have come across the opposite attitudes on occasion during my career as well. Things like an officer walked into an oral interview for a position as a Detective in the Major Crime Squad and says, "I've done just about everything you can do on this job; I've done it all", or when I was talking with another officer who was interested in detective work and he says he is an expert at getting people to confess and that has "a 100% confession rate." Really??

Make it a point to constantly seek new information and training, review journals and research within the field, stay active and on top of the current issues within your given field and be a lifelong learner. Above all, stay grounded and keep learning and growing as a professional!

I thought I would pass on a few good references for professional interviewers. These are a few of the books that I found valuable through the years regarding the importance of looking at the words people use:

Foundational:

• "Investigative Discourse Analysis" by Don Rabon
  • This is the very first book that I read...and re-read several times...on statement analysis which started my fascination and subsequent passion for the subject.  
• "I Know You Are Lying" by Mark McClish
  • This is a very good book on statement analysis and the power of looking at the words people use, and is an easy read. Mark is a retired U.S. Marshal and he reviews several famous cases.
• "Identifying Lies in Disguise" by WendellRudacille
  • Wendell provides a strong basis and understanding for the reader on the value of language and why it provides the interviewer with so much insight. 

Technical:

• "Forensic Linguistics" by John Olsson
  • This is a great book and introduction to the world of language, crime and the law. It is a much more technical book regarding the science of linguistics but provides the reader with a lot of information on language regarding a variety of topics such as plagiarism, suicide notes, ransom demands, authorship profiles, and dual authorship. 
• "Language Crimes" by Roger Shuy
  • This is another book from a linguistics perspective, but it provides an excellent perspective on how a linguist will use language in court. This is valuable information for investigators may end up in court testifying at some point.

When it comes to detecting lies and deception, the more reliable information and training we have at our disposal, the more effective we will likely be. Based on several international studies, most people rely on eye movement to tell if someone is lying or not. The common belief is that when people look away - gaze aversion - they must be lying because "they couldn't look me in the eye!" Countless research studies failed to support this belief, and in fact, this belief is so widespread that many times the liar will make a point to look you dead in the eye, because he too believes if he looks away you may not believe his lie. This is called "impression management".  

The video below is a short clip on micro expressions with Paul Ekman. By having good training with investigative interviewing and criminal interrogations, knowing what to look for and how to apply it within the contex of the interview, and adding skills like understanding and reading emotions and micro expressions in people will provide you with the much needed edge in your interviews and interrogations and assessments of truthfulness and deception in people.

Human beings are complex. You don't have to be a scientist or an academic researcher of human nature to know that is a true statement, you just have to live amongst us humans for a period of time and you understand. Well, you understand that humans are complex...not necessarily understand human behavior!

The point is, no matter how long we live or how long we have been in a particular profession, or how many experiences we have or how much training we have taken, there is always more to learn. One of the things I was always surprised with as a police supervisor was that many officers take one course on "interview and interrogation", which may be anywhere from 1 to 5 days, and they believe they have all the training they need in that area. That is simply not true. There is SO much to learn, and after 25 years I am still learning!

Police officers have mandatory training they must take each year, from firearms training to domestic violence issues, to how to use the latest computer databases. That is all well and good, but one of the things that police officers do the most, from the rookie on patrol to the seasoned homicide detective, is TALK TO PEOPLE. And not just talk to people like in a social setting or a cocktail party, they have to talk to people in a way to elicit as much relevant information from them while assessing for signs of deception and truthfulness. And they have to talk to people who are under stress, who have just been traumatized, who are under the influence of drugs or alcohol, who have elevated levels of anger and hostility, who may have memory issues, and who may or may not want to cooperate and provide them information. There are many, many more factors and complexities that make the "simple" act of communicating with and obtaining information from people so complex for the law enforcement professional.

This is one of the main reasons that it is so important to continually update your skills relating to interview and interrogation, read the latest information on detecting deception studies, associate with professional organizations on and off-line, read professional trade magazines, and attend formal training courses and academic conferences. Humans are complex...keep learning more and more about them.