The Economist has an interesting article on the ‘CSI effect’ which suggests that television crime dramas are altering jurors’ expectations of the relevance and power of scientific evidence and hence affecting how court judgements are made.
The article is largely based on a forthcoming paper to be published in Forensic Science International that argues the ‘CSI effect’ is influencing how forensic evidence is interpreted and understood by professionals and the public alike.
Nevertheless, both The Economist piece and the academic article in Forensic Science International are notable for the fact they are largely based on anecdotes.
Actually, empirical (shall we say, forensic?) evidence for the effect is harder to come by. One of the few people who have systematically investigated the effect is trial judge and law professor Donald Shelton who came to significantly less alarming conclusions.
In a study on the effect published in the National Institute of Journal, Shelton reported that although to effect did appear in places, it mainly effected expectations and the effect on actual decisions was inconsistent and largely insubstantial:
There was scant evidence in our survey results that CSI viewers were either more or less likely to acquit defendants without scientific evidence. Only 4 of 13 scenarios showed somewhat significant differences between viewers and non-viewers on this issue, and they were inconsistent. Here are some of our findings:
* In the “every crime” scenario, CSI viewers were more likely to convict without scientific evidence if eyewitness testimony was available.
* In rape cases, CSI viewers were less likely to convict if DNA evidence was not presented.
* In both the breaking-and-entering and theft scenarios, CSI viewers were more likely to convict if there was victim or other testimony, but no fingerprint evidence.
Law professor Kimberlianne Podlas was even more damning in a paper [pdf] published in the Loyola of Los Angeles Entertainment Law Review, writing:
Notwithstanding the popularity of such claims, they are not grounded in case-studies or statistical data of increases in acquittals. Rather, they are based on anecdotes about cases wherein law enforcement lost their case while believing it should have won. However, anecdotes are not an adequate substitute for empirical evidence or a logical theory of media influence.
The ‘CSI effect’, it seems, probably wouldn’t stand up in court.
UPDATE: Many thank to Mind Hacks reader Brett for emailing to say that the Stanford Law Review published an article on the supposed ‘CSI effect’ and why it lacks evidence last April, which is also notable for tackling the reasons for why it has gained a cultural foothold despite such flimsy support.