forensic evidence: witnesses & evidence

I wanted to talk about evidence and witnesses for my forensic research blog this time. While I don't go into evidence details in my stories, it pays to know the broad rules when it comes to evidence and witnesses. That way, if I have a character whose an expert witness, I can write that character in a believable way. Nothing ruins a story quicker, than a character that's weak or has a negative effect on the story. When it comes to witnesses, there are rules, or guidelines, that are applied to see if a witness will be permitted to testify. Two of those rules are Rule 702 and the Daubert Standard. These guidelines help the judge in the case to determine whether or not an expert witness should be allowed to testify.  These rules are in place to keep out testimony that is not rooted in facts or the product of reliable methods. I've seen some TV shows that play fast-n-loose with the rules to allow all kinds of last minutes evidence for dramatic effect, but in reality, there's more to it. 

So, why have expert witnesses at all? Well, since juries are composed of everyday people, it's difficult to understand all the forensic and medical details when you have a life of your own. I mean who has the time to research the details of DNA evidence when you have kids to take care of and bills to pay. That's where expert witnesses come into play, but can any witness be classified as an expert?  The answer is no. An expert witness is one that has training and experience in that area and even moot court experience is also required. If a witness is submitted as an expert and it is shown that their testimony that their training and background are lacking, then the decision to keep their testimony or not is left up to the judge. So, it pays to make sure your witnesses have all their "t"s crossed. 

In the end, evidence and witnesses have guidelines that they have to follow in order to be allowed in court. While the finer points will probably never be discussed in one of my stories, the broader concepts are very useful. As a fiction writer, I only use the general concepts and fill in the details. Which is probably the main reason why I don't want true crime or medical mysteries. For me, it takes a little of the "fun" out of reading by going too deep into the finer points. So, that's the short version of this part of forensic research. 
Until next time....