The way the article uses the term "truth serum" sort of implies that it usually works. Like, "he passed a lie detector test while on truth serum, so obviously they thought he was telling the truth". While it might have been something that was seriously considered, an aside something to the effect of 'though it was given more weight throughout history, 'truth sera' are not shown to produce conclusive benefits in lie detection' would have been a good thing. There are SO many myths about psychology, like the handy-for-movies idea of truth serums, and that would have been such an easy thing to not perpetuate.
Katherine Ramsland, Ph.D., an expert on murder and other shadow themes, teaches forensic psychology and has published 46 books.