June 15, 2006
Fewer experts, please

The defense team for Andrea Yates, in conjunction with a passel of mental health advocates, is challenging the qualifications of a prosecution expert for the upcoming retrial.

Yates' attorneys are challenging the qualifications of the state's expert witnesses, including Dr. Michael Welner, a New York forensic psychiatrist who evaluated Yates during a two-day period last month at Rusk State Hospital.

The issue is pending before state District Judge Belinda Hill, who will preside over Yates' new capital murder trial, scheduled to begin June 26.


The advocates who filed Wednesday's motion say that Yates clearly suffered from "severe postpartum psychosis" when she drowned her five children in a bathtub at the family's Clear Lake home on June 20, 2001.

But postpartum psychosis is an illness that is unfamiliar to many forensic mental health experts, the advocates said.

They argue that the integrity of the verdict is at stake, depending on which experts are allowed to testify in Yates' trial.

"Knowledge of the current research is required to ensure that the jury receives necessary information about postpartum psychosis and how it affected Mrs. Yates," the motion states. " ... The lack of expertise in the relevant mental health area presents the peril of misleading the jury."

The parties joining the motion included National Advocates for Pregnant Women, the Postpartum Resource Center of New York, Postpartum Support International and Texas Mental Health Consumers.

I have a lot of sympathy for the Yates team. Her illness is far less common, and far more pernicious, than postpartum depression. That needs to be clearly understood in order to judge her fairly. If they can make a reasonable case that any of these particular witnesses don't have an expert's level of knowledge about postpartum psychosis, then I think the judge ought to take a hard line on who gets to testify.

Having said that, I don't know what the case law is here. It seems to me that it's appropriate for the prosecution to question assumptions about Andrea Yates' condition - if they concede this particular diagnosis, it puts them in a tougher position, since in doing so they'd be admitting there's something unique and unusual about Yates. While I think Judge Hill should be reasonably strict about defining what expert status is in this case for the prosecution's witnesses, I also think she should give them some latitude in demonstrating what their bone fides are. If this all sounds a bit self-contradictory, it's another way of saying that I don't envy her the decision. I'll be very interested to see how she sorts it all out.

Posted by Charles Kuffner on June 15, 2006 to Crime and Punishment | TrackBack

The seminal case concerning expert witness testimony is the Supreme Court's 1993 decision in Daubert v. Merrill Dow Pharmaceuticals, Inc. The Texas Court of Criminal Appeals adopted a similar test in 1992 in Kelly v. State and then explicitly adopted the Daubert standard in 1997 in Hartman v. State.

The law governing the admissibility of expert witness testimony is complex and voluminous. In essence, however, a judge is supposed to act as a gatekeeper to prevent unreliable and unhelpful expert testimony from reaching the jury. Judge Harvey Brown, in his 1999 Houston Law Review article, "Eight Gates for Expert Witnesses", summarized the eight gates through which an expert's testmony must pass before it can be considered by a jury:

1. The expert's testimony must assist the jury in reaching its decision. If the jury is equally competent to examine an issue, the expert's testimony is not helpful.

2. The expert must be qualified to give each opinion, and if an opinion relates to a specialty within a field of expertise, the qualification must be tied to that specialty.

3. The testimony must be relevant to an issue in doubt that the jury is being called upon to decide.

4. The methodology used by the expert must be sound; that is, based upon reliable principles and methods.

5. The foundation of the expert's opinion must be reliable; that is, the assumptions used must be reasonable and the data used must be reliable and sufficient.

6. The expert's opinion cannot be based upon inadmissible evidence (evidence the jury is not allowed to consider) unless that evidence is of a type reasonably relied upon by experts in the particular field.

7. The expert must use sound reasoning to extrapolate from the base data and assumptions to the conclusion of the opinion.

8. The expert's opinion may not be unfairly prejudicial to the opposing party.

From your description, it sounds like Yates's attorneys are attempting to attack the prosecution's experts through the second gate, on the experts' qualifications. The party offering an expert must establish the expert's "knowledge, skill, experience, training, or education" regarding the specific issue before the court that qualify the expert to give an opinion on that particular subject. Malone v. State, 163 S.W.3d 785, 793 (Tex.App.--Texarkana 2005, pet. ref'd); see also Broders v. Heise, 924 S.W.2d 148, 153 (Tex.1996).

Posted by: Kenneth Fair on June 16, 2006 12:49 AM