Thursday, February 19, 2009

Forensic Science?

I just downloaded a copy of the 254 page report by the National Academy of Sciences on the state of forensic sciences in the United States. Entitled, Strengthening Forensic Science in the United States: A Path Forward, the report is must reading for criminal defense lawyers. Press accounts and blog chatter are ringing now with claims that forensic sciences are "BS." I will reserve judgment until I actually read this report.

Two points seem worth making at the outset.

First, there really is no such thing as forensic science. There are core sciences and applied sciences. These techniques and methods of investigating things yield results that are more or less reliable. Calling something forensic merely means it has been prepared in anticipation of a court proceeding.

Last week, I had a forensic toxicologist on the stand. On direct, he could not throw the word forensic around often enough. On cross-examination I asked him whether he agreed with me that calling a science forensic added no scientific value. He said he would have to think about it. Later he agreed. All it means to call something forensic is to say it was prepared for preparation in the "fora," or court. There is no scientic method known as forensic. The public is seduced by the fancy sound of the word.

Finally, this report seems to suggest that courts are also often hoodwinked. I recall a case of mine years ago involving bitemark evidence. The state's forensic odontologist relied on digitally enhanced photographs of the victim's breast in claiming that my client had bitten her. When I challenged the expert to tell the court how a digitally enhanced process had accounted for the three dimensional curve in the two-dimensional image of the victim's breast, the expert could not. The court permitted the testimony, saying it went to its weight, not to its admissibility. When the Supreme Court later ruled that it was error to admit this testimony, it was too late: The Court found the error harmless. I wonder about that to this very day.

Judges fail when they let questionable evidence in and avoid responsibility because a jury must assess the weight of the evidence. Most jurors, and most lawyers, don't know enough science to question an expert's pronouncement. The new NAP study suggests we all need to do our homework and fight a whole lot harder to keep junk science out of the courts.