Sunday, February 22, 2009

Faulty Forensics?

This week a report came out from the National Academy of Sciences entitled "Strengthening Forensic Science in the United States: A Path Forward." It was a congressionally mandated study from the National Research Council and it basically states that there are serious deficiencies in the forensic science system and calls for major reforms and new research in the field. They recommend mandatory certification programs and stronger standards and protocols for analyzing and reporting on evidence. They also think that there is a scarcity of peer-reviewed studies establishing the scientific bases and reliability of many forensic methods.

This came as a really hard blow to my entire community. The only science that isn't really being challenged is DNA technology and that discipline is probably the reason that every other one is under such scrutiny. Researchers have mapped the entire human genome. There are stats in DNA.

Not so for many other sciences - yet this is what the report wants, every discipline to be able to report some sort of stat and a known error rate. The problem is that DNA is relatively unchanging so those numbers, those stats, they aren't changing much either. However, (for example) fibers are changing constantly. Not only fashion, but fiber technology (nanofibers, anyone?), what people purchase, the fading of dyes, the inconsistency of dye lots, and what products are manufactured from is always changing. How are we ever to keep on top of this? Will knowing that a certain fiber is owned by 16% of the population help at trial? What if half of those fibers are dyed blue? Does that change anything? Is that something we can track?

What people don't seen to understand is that all evidence is not individualistic. If you get a good DNA profile from something, sure, we can identify it to a specific person. Fibers are not that sort of evidence. Fibers are the sorts of things that have similiar characteristics, to the point where one sample is indistinguishable from another. Can fibers from two different sources look the same? Absolutely. Can a victim have fibers on them that look just like fibers from a suspect that did not come from the suspect? Absolutely. Might they have come from the suspect? Yes. Might they not have? Yes. The problem is that the science isn't completely discriminating.

One its own, this evidence doesn't necessarily mean a lot. But if we have lots of this evidence stacked against a suspect, well, then it probably will lend more weight to a jury. It there is an abundance of it, maybe it means more. But you see, that's not for forensic science to decide. That is the jury's job. It is the forensic scientist's job to make the jury understand what the evidence means, and I believe that this is where the breakdown is occurring. Most of us are not teachers, and I dare say that some of the jurors either aren't interesting in learning, have already made up their mind about the case by the time we take the stand, or didn't bother listening to what we had to say. There are many of us who have caught jurors nodding off in the box.

A case study example from The Innocence Project:

On March 12, 1981, the victim in this case was walking along a road looking for help after her car blew out on the railroad tracks. A black man walked up to her, accosted her, threatened her, grabbed her by the neck, and dragged her from the road to the side of some buildings. He pulled her hair, punched her in the face, choked her, and bit her. He then ordered her to take off her pants, stockings, and underwear, and then raped her. He repeatedly choked her and hit her head with a pipe. After the rape, the assailant cleaned the victim's fingernails with grass. The victim ran away and was picked up by Deputy Domangue in a patrol car. Domangue identified Charles as a hitchhiker whom he had ordered to get off the road an hour before the crime was committed. The victim later identified Clyde Charles as her assailant in a one-on-one show-up at Terrebonne General Hospital. The defense claimed that the deputy gave the description to the victim before her identification. Nevertheless, Clyde Charles was convicted of aggravated rape on June 22, 1982, and was sentenced to life in prison at the Angola penitentiary.

The prosecution's evidence included the the victim's identification at the one-on-one show up and her testimony that the rapist called himself Clyde. A microscopic hair analyst discovered two Caucasian hairs on Charles's shirt and testified that they were microscopically "similar," but not conclusively identical, to hair from the victim's head. Because there is not adequate empirical data on the frequency of various class characteristics in human hair, an analyst’s assertion that hairs are consistent or similar is inherently prejudicial and lacks probative value.

Deputy Domangue's testified that Charles was wearing a dark jogging jacket with white stripes when he saw him (the victim testified that the rapist wore a dark jogging suit with stripes) and that Charles was wearing a red cap and blue jacket tied around his neck when he found him hitchhiking. The police found a red baseball hat and blue jean jacket near scene of the rape and Charles had admitted that he had been wearing a blue jacket. The prosecution also introduced spermatozoa found in the rape kit.
This came from the innocence project, which is why it says: "Because there is not adequate empirical data on the frequency of various class characteristics in human hair, an analyst’s assertion that hairs are consistent or similar is inherently prejudicial and lacks probative value." I have issues with this statement. Yes, we do not have empirical data to tell you how frequently these characteristics all happen together, but that doesn't mean that it's prejudicial or lacks probative value.

They claim that the reasons Clyde was falsely imprisoned were because of an "Eyewitness Misidentification and Unvalidated or Improper Forensic Science". It's true he was misidentified by the victim. It is not true that the science was faulty. The jury just didn't understand exactly what it meant.

Although, if you were on a jury and the victim pointed out the suspect and all the other information was relayed to you, excluding the hair information, I bet you would be hard pressed to find him not guilty. The point I'm trying to make is that it's not all forensic science's fault. Everyone performing the analysis is human, prone to errors, but so is the jury. And the jury is made up of people who may not understand what they are being told, or understand the legal system... or understand exactly what "beyond a reasonable doubt" means.

There are so many confounding factors well beyond the scope of the report. I haven't even touched on most of them. But it has everyone I know in an uproar. And probably all defense lawyers chomping at the bit to get us on the stand and try to discredit us because of this report.

Well, lawyers, it's time that you take some of the blame as well. The forensic scientist can not control how their testimony is spun in the courtroom, particularly during closing statements.

But I digress... There are so many things I haven't touched upon, like fingerprints. I'm having a hard time with cohesive ideas about this particular topic because it's so close to my heart. I can't begin to go into every thought I've had on this matter and it really gets me into an emotional uproar thinking about it... so, I shall leave you with this thought:

The Innocence Project has only released 230 people who were falsely imprisoned out of all the people thrown in jail every year. What these activists refuse to admit is that forensic science may very well be the leading preventer of wrongful convictions. Why don't they give me a stat on how many guilty people have actually gone free? Oh, that's an unknown? It's an impossible stat to figure?

Welcome to our world.

End Blog.

1 comment:

Nikki said...

PS - It's not that I want these innocent people in jail. Far from it. I am very grateful for the work that the Innocence Project has done. I just don't think that they need to drag forensic science through the mud to do it. It doesn't deserve that. In fact, they should be thanking us for advancements in DNA technology that is freeing these people.

Also, I support research in the field and would really enjoy the feds giving us money for support... because we need it, and don't get enough of it. I would also really like it if I didn't have to write another grant to get it.