

Eh… They do actually work for most people, unless they have been trained or take drugs to beat them. There is also a small portion of the population that will just throw false positives all over the place due to anxiety. Those are the reasons it’s not admissible in court. People take “not admissible in court” to mean polygraphs don’t work at all and are a pseudoscience, but really they work for like 95% of people.
Her main protagonist is a rich jock who grows up to be a cop. What did you expect?