Forensic Psychiatry--How Do Forensic Psychiatric Investigators Know if a Perpetrator is Lying?

When forensic psychiatrists interview a suspect in a crime, they use several tools to get the information they want. However, that does not come without a price. Perpetrators of a crime will knowingly engage in any type of deception in order to fool the investigator any way they can.

Suspects are very likely to lie, without taking into account whether they see forensic psychiatrists as enemies or probable associates in deception. If perpetrators can convince forensic psychiatrists that they are truthful, do not remember anything about the crime, or that they are simply crazy, then they definitely have an ally in court.

For instance, suppose a suspect is no doubt guilty of a sexual assault or murder but shows that he has respect for women, when in fact he does not. The perpetrator may prevaricate about past interpersonal and sexual confrontations, change or completely make up beliefs and feelings all with the expectation of being declared incompetent to stand trial and thus circumvent any responsibility in the crime. Many times such exaggerated stories are clones of symptoms that the perpetrator believes will end up in a well-known diagnosis such as posttraumatic stress disorder (PSD), multiple personality disorder (MPD), or whatever else they have seen in the media.

Malingering is a special form of deception in which the subject tries to make any physical or mental defects seem worse than they really are or fabricates them entirely. On the other hand, subjects may attempt to make a defect seem less severe than it really is. Fortunately, there are personality tests as well as several other kinds of tests that can be used to determine if the subject is lying.

Police officers, lawyers, psychiatrists, and many other people who come across criminals and suspects regularly become skillful at detecting deception. There are several techniques, though none of them are uniformly dependable, used to detect if a person is lying. They include:

• Looking for signs of nervousness
  
  Many people become nervous when questioned by law enforcement authorities. Sometimes signs of nervousness can be indicative of lying. Profuse sweating, pupillary dilation, tremors of the hands and lips, failure to make eye-to-eye contact, and hesitation and fast speech can be indicative that a person is lying.



• Reading body language
  
  Noting how the subject sits or moves in his chair may indicate deception. Such signs include twisting together of clasped hands, slouching, tapping of the fingers, fidgeting, and many others.



• Using neuro-linguistic programming (NLP)
  
  NLP is a method of reading a person's eye movements to ascertain his or her mental state. Looking up and to the left while answering questions may be indicative that the subject is remembering something he has seen. NLP, however, is extremely controversial and has no scientific basis.
  
  If you have watched the movie The Negotiator starring Samuel L. Jackson and Kevin Spacey, you would have seen an example of NLP in use.

These are some of the many tools that forensic psychiatrists or investigators use when interrogating a suspect involved in a crime.

If you are a big fan of the CSI TV shows, watch how the suspects act under interrogation. You will see good examples of the aforementioned techniques. If you have ever watched the reality TV show The First 48 on the cable channel A&E, you will see real-life examples of suspects engaging in deceptive techniques while being interrogated by police.

Fabiola Castillo is an online marketer for the website NinjaCOPS.com. This virtual store specializes in personal defense products where you can buy the best pepper spray, kubaton keychains, hidden video cameras, cheap stun guns, nunchaku tricks videos, telescopic steel batons, and many other home security products.