Also, from a more practical perspective: what if the person just has a minority view on some issue? Should he be thrown in prison just because a lot of people think the methods he uses are unscientific? Remember the majority is not always right.
A conviction is supposed to be based on guilt that is beyond a reasonable doubt. If there is credible scientific disagreement on a method or procedure of forensic science, but an expert's testimony to a jury just says "so my science has proven xyz", then he may cause the jury to believe something is beyond a reasonable doubt when it is not.
Finally, even if your entire hypothesis were correct, you still shouldn't give a witness the same sentence as the defendant he wronged. You'd be punishing the witness MORE than the defendant, because the defendant is typically exonerated before he's served his entire sentence.
Minor repair - the witness serves whatever term the defendant has. If the defendant served six years of a life sentence and then was exonerated on proof of innocence, the false witness gets six years.
Punishing an expert the same amount as the person he helped convict would be a disproportionate punishment. Remember, the expert was merely negligent, he didn't have a depraved mind nor did he actually mean to wrongfully convict someone. To say that a negligent witness should receive as much harm as he accidentally caused is counter to our intuitive sense of what is just, and is also inconsistent with how our justice system operates.
Our justice system generally only uses "eye for eye, tooth for tooth" when the perpetrator fully intended the harm he caused. That's why we punish those who commit manslaughter less than those who commit murder. If you really think that a negligent witness who accidentally causes an unjust life imprisonment should get a life sentence himself, why shouldn't everyone convicted of negligent homicide be automatically sentenced to the death penalty?
That's a very good point.
-It's not the usual case, but sometimes it is clear that the witness knew better, so he must have had intent
-In cases where we infrequently are able to catch the wrongdoer, sometimes the punishment will exceed the crime just to make the deterrence efficient
-Those are accessory issues. The real question for me is, does the nature of expert testimony preclude the applicability of intent? Put in other words, when an eye witness identifies a suspect, people will look at that and think "so it is the opinion of this witness that the suspect is guilty". When an expert testifies on the basis of forensic science, they typically won't present it as "this is my opinion" but as "this is objective, repeatable, provable fact". The whole point of forensic science as such is that the personality/intent of the scientist is supposed to be irrelevant. My question is, is it fair for this to work both ways?
Perhaps? a better way wouldn't be to punish the witness, but add rules to how the evidence can be presented and instructions given to the jury. Can we change things up so the jury perceives that the testimony is just another credible opinion (and they can know what makes it credible and how much so)?
An alternative way to think of this in economic terms: There is a risk and a cost that science is inaccurate - or that the science was accurate but the distinction of what is and isn't proven by the science gets muddled (this tends to be the most common problem with expert testimony). The scientist/expert is the one generating the risk, but the defendant is the one that might pay for it - this is an externality. If the scientist/expert knows that he could face the same risk, then we've internalized the externality. Hypothetically this should reach an efficient outcome, where the certainty of the claims the expert makes is balanced by his own fear of the risk.
Anyway, I know as a generalization that it's impossible to have a perfect system, but when I read specific instances of what sometimes goes wrong, the ruin to an innocent person's life because of false testimony, I get riled up pretty easy. Maybe this isn't the best fix, it just seems like there has to be something we can do.
Region IV AlumnusCog Debate
"But I declare that Carthage must be destroyed."
Cato the Elder