Last week, a young lawyer lectured on the growing use of DNA evidence at the law school. I found her lecture simply fascinating and thought-provoking. The whole science of forensics has gained popular attention in recent years, both through its use in cases like the Peterson murder trial and because of the increasing popularity of television shows like CSI.

I was particularly interested in this young lawyer’s perspective on the use of DNA. She was concerned about what effect the use of DNA evidence would have on the court system and on the prison system as it now exists. She made several points worth repeating.

First, she drew attention to the fact that the techniques for DNA recovery and testing are rapidly improving. Forensic scientists now need only six cells to run DNA tests. That means, in effect, that anyone who touches anything is likely to leave enough of a DNA trace to be recovered.

She also pointed out that DNA is not just used in cases involving violence against people, i.e. murder, assault, rape, but also is being used more frequently in property crimes. In the past only a small percentage of property crimes have been solved. The vast majority of crimes such as burglary or car theft have gone unsolved. That is now changing because of DNA evidence taken from the recovered property.

In addition to the fact that DNA evidence is permitting law enforcement investigators to identify more suspects in more types of crimes, there is also the fact that DNA evidence is very powerful precisely because it is scientific evidence and has about it an “aura” of definitiveness. Indeed, many crime investigations today involve what are known as “cold hits,” where the only evidence may come from a DNA sample. Juries, when confronted with such evidence, may well tend to believe it just because it is “high tech.”

There are a number of dangers in this, however. First, of course, scientific evidence is only as good as the scientists and investigators who produce it. If the forensic scientists are sloppy or incompetent, the evidence may well be worthless. Juries will need to be convinced that the evidence has been collected and processed properly.

This need for juries to understand and judge the process involved in the collection and processing of DNA samples worries me quite a bit. The fact is that forensic science is not simple stuff that anyone with a grade school education can fully understand. It is often rather complicated and quite difficult to understand fully. Will juries be able to understand these complexities sufficiently to decide whether the evidence is trustworthy?

I read a report recently on problems encountered by people using Web sites designed for diabetics. Apparently, much of the scientific information provided for these readers is beyond their comprehension. If folks cannot understand the information provided on such Web sites, information in which they have a personal interest, how likely is it that they will be able to understand complex forensic evidence about DNA in a court?

Another issue this young lawyer raised that I also found worrisome was the potential impact on law enforcement and the prison system if a greater percentage of crimes are solved because of new techniques like DNA tracing. She pointed out that our already overburdened legal system depends upon the fact that a large number of crimes will go unsolved. What will happen if, as a result of DNA testing, state and federal law enforcement agencies begin to solve a far higher percentage of crimes and the perpetrators of such crimes are prosecuted and found guilty? What might very well happen is that courts will become even more crowded with criminal cases that result in guilty verdicts.

When one combines this with the growing use of sentencing guidelines that mandate prison time, we may soon find ourselves with a much larger prison population. Who will pay for all the new judges and prisons? Perhaps, we will need to rethink what crimes will bring prison time!

A final note. As we sit down Thursday to share Thanksgiving with family and friends, we must not forget all the men and women in the U.S. military who are spending the holiday away from home and in peril. Let us all say a prayer of thanks for their sacrifice and hope that next year they may be here at home safe and secure.