The very first impression a subject forms of an investigator will be based on physical observations -- not only gender, race and body type, but also attire. The desired perception a subject should have is that the investigator is professional, intelligent, non-judgmental and trustworthy. Anyone who has found themselves in a social situation of being either under or over-dressed can appreciate the psychological impact attire choices have on social interaction. The other fascinating aspect of attire is that it affects a person's self-image which, in turn, can affect confidence and performance levels. For example, if a person knows that there is a coffee stain on their shirt they are unlikely to draw attention to themselves by being assertive or vocal during a conversation.
Investigators who wear uniforms do not have a choice of attire. The authority associated with a uniform is beneficial during an interview. That is, a guilty suspect will experience greater fear and anxiety when lying and exhibit more behavior symptoms of deception. However, this effect is undesirable during an interrogation. During an interrogation the investigator's uniform, gun and badge all serve as reminders of the punishment the suspect faces if he tells the truth. It is, therefore, our recommendation that if an investigator must wear a uniform when conducting an interrogation that a comment be made to the suspect to negate the consequences associated with the uniform, e.g., "You know Mike, at 5:00 I take this uniform off and put on jeans and a sweatshirt just like you're wearing. In many respects, you and I are quite similar..."
Many investigators work in plain clothes and have a choice of what to wear each day. Consider a person who is dressed in a $700 suit, with a silk tie, starched and pressed white shirt and highly polished black wingtip shoes. In a board room this wardrobe may portray success and knowledge with an expectation of respect. However, when inside an interview room with a robbery suspect, this attire takes on a completely different meaning. The suspect is likely to resent an investigator dressed in this manner for being able to afford such expensive clothing. Also, the suspect may not trust the investigator, perhaps believing that the investigator's fancy clothes are an effort to somehow put the suspect "in his place," or are the product of accepting bribes or kickbacks (picture well-dressed drug dealers). Both of these perceptions, obviously, are undesirable.
The underlying psychological principle regulating investigator attire is this: there is a natural tendency to respect and trust people who share similar behavioral choices, including choice of clothing. A person who primarily investigates white collar criminals and deals with professionals on a regular basis should, therefore, dress at the subject's level. This probably will mean a suit or sports jacket and tie for men and business dress or suit for a woman. This "business attire" affords some flexibility where a suit coat an be removed or a tie loosened. Very clearly, it is undesirable to have a situation where the suspect is dressed significantly better than the investigator.
Many law enforcement investigators routinely deal with street criminals and gang members. When these suspects are picked up for questioning they may be wearing tennis shoes, jeans and a T-shirt. Does this mean that the investigator should dress down to the suspect's level? We do not think so. To maintain a perception of authority and competency, the investigator will want to at least dress in casual business attire. Examples of casual business attire include a dress shirt or short-sleeve knit shirt and khaki pants for men and a blouse and pants for women.
The previous comments have all related to subject perceptions during an interview or interrogation. There are additional attire considerations when it comes to testifying in court where the visual appearance of a witness is sometimes more important that what the witness says. If a uniform is worn to court the investigator should make certain that it is clean and pressed and that shoes are polished. If the investigator is working undercover and therefore is unshaven and wearing his hair in a pony tail, he should still dress in a professional manner and make certain that the prosecutor asks questions to allow him to explain his physical appearance.
Investigators who testify in plain clothes should obviously dress professionally. A suit and tie is appropriate for male investigators and a business dress or blouse and pants for female investigators. The female's blouse or top should have a conservative cut. There are also subtle color considerations to keep in mind. The colors blue and brown are associated with authority and control(think of colors for military or police uniforms). Grey, tan or green are social colors that invite interaction and acceptance, e.g., the psychologist's or professor's wool tweed jacket. The guideline I follow is that when testifying for the defense I wear authoritative colors. Conversely, when I am called by the prosecution I want to avoid an authoritative image and will wear social colors.
Many years ago a popular book titled "Dress for Success" stressed the importance of how one's attire can significantly influence the perceptions of other people. One underlying premise was that if the reader wanted to obtain a position that paid $200,000 a year, he or she first had to dress in a manner consistent with someone in that salary bracket. I'm not certain about that theory but we have anecdotal accounts where an investigator's attire appeared to contribute to the success or failure of an interrogation. On the one hand are the over-dressed investigators who are perceived by the suspect as condescending, arrogant and clearly an adversary. On the other end of the continuum are the unkempt, disheveled investigators who come across as uncaring, sloppy and incompetent. As previously stated, the proper attire for the investigator will depend on the suspect. Before entering your next interview look in the mirror and ask yourself, "How will this particular suspect perceive me?"