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Unproven investigative technique used widely by police

Many New Jersey residents may expect police investigations to be like those often portrayed in movies and TV dramas, focused on accuracy and taking advantage of the latest advanced scientific techniques. Unfortunately, however, some investigations and forensic techniques are fraught with pseudoscience and questionable tactics that allow police to go after a suspect they have already decided is guilty, regardless of the potential of a different perpetrator or the original suspect’s innocence. Many techniques used by police, despite being taught in classes paid for by police departments around the world, are scientifically unproven and highly unreliable.

One of these techniques is called Scientific Content Analysis, or SCAN. The creator of the program argues that it can make investigators into “human polygraphs” determining whether or not a suspect is responsible for a crime during an interrogation. The basis of the technique involves asking a suspect to write out a narrative of the events surrounding the crime. After that, a police officer trained in the technique will go over the statement, looking for grammatical quirks that allegedly point to signs of deception.

However, despite being used nationwide, the technique has little scientific backing. Experts in deception who have studied SCAN say that it is broadly unreliable and offers a patchwork set of criteria that are more likely to confirm a police officer’s existing beliefs than provide a mechanism for scientific analysis. Language fluency, educational levels and learning disabilities may all influence the outcome of a SCAN analysis.

Techniques like SCAN continue to be used widely in police stations, one reason why many experts advise people to avoid speaking to police without representation, even if they are innocent. A criminal defense attorney may help people to protect themselves from unfounded allegations and work to prevent a conviction on criminal charges.



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