A recent television series documented a case in the United States revolving around a man accused of murdering his wife. In the criminal case, the prosecution used testimony from an expert witness to claim that the man staged the 911 call and was actually himself the murderer. He was convicted based on the testimony of a sergeant who interpreted the 911 call as being staged. A jury convicted the man on that basis.
The basis for the witness’s testimony is a little-known method of lie detection promulgated by police departments and the FBI. According to these departments, you can tell if a person is lying by interpreting linguistic cues and stress in their voice. Of course, there is little scientific basis for this, and there has been no testing to determine the veracity of these claims. That’s not the problem, however.
In most cases, we would laud anyone who wanted to endeavor to determine if there was any method to determine if someone was lying by studying their vocal cues. That’s not what’s happening here, however. Instead, the police departments are assuming that they can do this without subjecting their procedures to peer review. Even those most familiar with the theory have publicly stated it should not be used to convict individuals. Nonetheless, there have been 100 cases (at least) throughout the U.S. in which 911 call analysis or vocal stress interpretation.