Witness for the Prosecution" about a neuropsychologist who frequently is retained to testify on behalf of the state in criminal trials. The expert witness gets criticized for slanting his opinion in favor of the prosecution by ignoring previous history or making certain presumptions about the defendant's previous education or experience. You can read the article yourself, I won't repeat it here.
The article quotes questions from the doctor's cross-examination about the assumptions he based his opinion on: how do you know the defendant took a psychology class? Why are you ignoring or not considering his mental health history? Why are you disregarding DSM diagnostic criteria?
All of this sounds pretty horrible, but the fact of the matter all the questions asked by the cross-examining attorney at the beginning of this article are routine questions that will get asked of any testifying expert. As I mentioned at our recent talk at the Johns Hopkins Odyssey lecture, these questions are designed to make the expert look incompetent or foolish. They are an attempt to undermine the credibility of the expert in the eyes of the judge or jury and to get him flustered and confused.
This is predictable, and to a certain extent it's a choreographed dance. When you express an opinion you will be asked the basis for that opinion---what information did you consider, did you have all the information, why do you rely more heavily on one source of information than another, did you consider the credibility of the information?
The next step is to alter all the details slightly in an attempt to get your opinion to waver or even change: what if this piece of information weren't true, or you found out a certain fact was different from what you assumed? How would this affect your opinion? This step of the process could go on for hours. It can be painfully boring for a jury, so when the NYT article talks about the importance of "presentation" and communication for a good expert witness, that's why. You have to hold a jury's attention for hours in spite of excruciatingly detailed questions, a court room that is either too hot or too cold, and chairs that you can't quite get comfortable in no matter how you twist.
Once all of this is exhausted the last stage is to attack you, personally. If you don't have the guts for this, if you have an issue in your professional past you'd rather not have public, this is the stage that will weed you out of the expert witness field. I note that the NYT article mentioned the expert's appearance on his Facebook profile, and also mentioned he had a Twitter feed. I plan to send this article to my students to remind them that anything they write, anywhere, could theoretically end up on the New York Times web site. I certainly keep this in mind when I blog and tweet. This is the chance you take when you do forensic work, whether or not you are forensically trained.
The last point I'm going to make using this article is the fact that this particular expert is retained as a prosecution expert. There are both advantages and disadvantages to being retained by one side or another, as opposed to working as a neutral court evaluator as I do. A defense expert has the advantage of being able to get in to see the defendant as soon as possible after the offense. This is good because you're more likely to get an accurate picture of the defendant's mental state at the time of the crime. A state or court's expert sees the defendant weeks or even months later, after bail review and arraignment and after the defense expert has had a chance to advise counsel on the likelihood of a viable insanity defense. Experts acting in a neutral court-appointed role have to work harder to gather the data to put together a retrospective picture of that mental state.
I could go on and keep rambling about this but that's enough for now. The NYT's point about the expert being a hired gun as an old one I've talked about before. Ironically, the NYT just made my point about this---if you are a hired gun everyone will know it, it will undermine your credibility and make you less useful as an expert. Being a hired gun is bad for business so most experts know you just can't get away with it over the long term. And that's one of the standard cross-examination techniques as well---trying to paint you as a hired gun.