Tag: Casey Anthony

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Junk Science in Court: Bite Me

If you were charged with a crime in the U.S. and put on trial, would you assume that the forensic evidence introduced in court against you would at least be based on some kind of sound, factual, scientific research? Think again.

Frontline recently ran a documentary on the “science” of fingerprinting, bite mark analysis, and other forensic “sciences” and demonstrated rather convincingly that many courts will allow testimony by self-styled experts that has no basis in any substantive research whatsoever.

The most dramatic examples were related to two men who had been in prison for ten years or more for assaulting and murdering three-year-old girls. In both cases, the men were the former boyfriends of the girls’ mother. In both cases, an orthodontist who claimed to be versed in the science of bite mark analysis testified that scratches on the little girls’ bodies were actually bite marks that could only have come from the suspects, to the exclusion of everyone else. In each case, this testimony was the bulwark of the prosecution’s argument. In each case, the judge allowed the testimony. In each case, the man was convicted. In each case, DNA analysis– which is founded in real science– eventually exonerated the men, and the real killer confessed to the crimes.

Do I have to be polite when expressing myself about how I feel about these judges for allowing this testimony into their courts? This is not a matter upon which reasonable, educated people might respectfully beg to differ. These are witch trials that have no place in a civil society.

How far does it go? At the Casey Anthony trial a self-styled expert in smells testified that a container of smell– I’m not making this up– from the trunk of Casey Anthony’s car contained the smell of a dead body. Casey Anthony was found not guilty largely because she was able to raise $200,000 for decent lawyers by selling pictures of her with Caylee to People Magazine. Those lawyers successfully challenged a host of junk science evidence.

Now, there are rules about “expert” testimony. Prosecutors interviewed by Frontline didn’t seem aware of them. One of them declared that it was up to the jury to determine whether the smell evidence was truthful, relevant, or accurate. It is not. The Supreme Court has ruled that the judge is the “gatekeeper” for expert testimony and determines whether any specific evidence should be presented or not.

Furthermore, evidence will be deemed qualified if it has been gathered according to a scientific methodology which makes use of valid scientific procedures. One key element is falsifiability.

That said, some judges will permit both sides to present evidence on the scientific validity of certain procedures and expect the jury to sort it out. This gives an enormous advantage to the heavily resourced prosecution in most cases.

My own take on the Caylee Anthony case? I doubt we’ll ever know the truth. Casey Anthony is clearly a disturbed, unstable, delusional young woman, but that doesn’t necessarily mean she is also a murderess. She could be. But we’ve seen enough wrongful convictions to know that people tend to fit the facts to the preferred narrative, not the other way around, and whacky, unstable people are particularly vulnerable.

Here’s the most compelling point in her favor: if the police and prosecutors really believed she was guilty, why on earth did they introduce so much whacky junk forensic science into the proceedings? If you were a prosecutor, wouldn’t you have dumped the “smell” science immediately as something that looked specious and stupid, and would ultimately weaken your case? If you really believed in your own case, with any kind of integrity or intelligence, why would you introduce so many dubious elements into your presentation?

The answer is that prosecutors and police believe that the court system is a bit of a game, and you do what it takes to win, and getting at the truth is merely a secondary objective. I think they see a kind of organic logic to the system, justice theatre, in which their goal is to lock up bad people when something bad happens. If a few innocent people get snagged along the way, so be it.

And if a particular suspect didn’t commit a particular crime but was busted for it anyway– it’s a small price to pay for a system which, they believe, ultimately “works”.

When I was very young, my brother came into our house one day and told me he needed help. He led me to the back of the garage where he had started a fire which was now beginning to lick up the exterior wall. He wanted me to help him put it out. We began filling small plastic buckets with sand from the sand box and throwing it on the wall. In spite of our efforts, the flames grew bigger and bigger, and I believe I was about to tell him we should get real help when I noticed he had disappeared. He had gone back into the house to tell our mom that I had started a fire behind the garage.

I denied it, of course. My mom stared at me and ask me if I was telling the truth. Everybody knows that if you are telling the truth, you won’t get nervous and giggle. I giggled. Busted.

Or maybe I wasn’t. I had a feeling that Mom wasn’t totally convinced. I don’t remember any big punishment other than having to stay in my room for a while.

We now know, I hope, that people giggle when they are nervous, whether they are lying or not. It was the bite mark of my childhood, a wrongful conviction based on spurious evidence. You might think it trivial, but I have never forgotten. I few years ago, I brought it up at a family party and my brother acknowledged that he, in fact, had started the fire. Within a year, the entire family seemed to forget that revelation and went right back to blaming me for it.

, and even to this day my siblings tend to remember that I started that fire rather than the fact that Ed finally admitted the truth years ago.

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Your Fingerprints: Junk Science

When we were little children watching police shows like “The FBI” and “Adam-12” on TV, we became convinced, along with everyone else, that if a criminal’s fingerprints were found at the scene of the crime, it was case closed, proof-positive, open and shut.

Why? Because no two fingerprints, in the entire world, could be alike. How did we know that? How did we know that that was true? Because everyone acted as it it was true. Everyone acted as if no two fingers in the entire world could have matching patterns on them. Everyone acted as if this was the product of years of sound, thorough research conducted by revered scientists.

It is very odd, then, to discover, that there might never have been a good reason for believing that the evidentiary value of fingerprints has ever been established with any kind of scientific rigor. There really is no body of systematic research or scientific proof that fingerprints really are unique to each individual, at least, not in the way the movies and television would have you believe. In other words, nobody has ever systematically compared fingerprints to each other to establish just what the odds are that any two, from perfect strangers, might match.

In 1995, a proficiency test was administered to 156 law enforcement examiners. These are the guys called in to court to testify that the suspect’s prints — don’t forget, we could be talking about Lee Harvey Oswald here, among others– were found on the murder weapon, or a door knob, or a table surface, or something. Only 44% of these “experts” could correctly identify all five of a set of test prints. Read that again: less than half of the “experts” were proficient. And again: half of these guys got at least one of the prints wrong, out of five. Twenty percent. One in five.

I don’t know the details of the test, but I do know that the people who administered it considered the performance of half the experts to be inadequate and unreliable.

What has happened is that the Supreme Court of the United States has recently made some rulings that require courts to establish that “scientific evidence” really is scientific before it is allowed in the courtroom. What you have to imagine is some “expert” talking in obscure, difficult language about some scientific information which the jury doesn’t understand. The jury takes the guy’s word for it. The jury figures that the “expert” knows. The jury figures that he wouldn’t be testifying this way if he didn’t have a solid body of research and knowledge behind him. Think about fiber and hair analysis. Think about fingerprints. Think about those difficult cases where the prosecution actually has very little evidence so they scrounge around for “matching” fibers and hairs and semen and spots of blood. We have been trained by television and the movies to regard such evidence as definitive and decisive. Now we are beginning to know that such evidence can be constructed around a suspicion.

In France, 16 points of similarity, between fingerprints, are required before a “match” can be asserted. In Sweden, the number is 7. The FBI, in the U.S., won’t tell us how many it considers decisive. The FBI says it decides on a case by case basis. I thought that justice is exactly the opposite of that. Blind and impartial. Consistent. The FBI says, “trust me”. I wish I could.  Science does not provide standards that apply on a “case by case” basis.

Our system of justice– adversarial– encourages both sides to become advocates for their clients’ interests, rather than the truth. The police don’t just present facts– they invest in the suspect’s guilt, and advocate for it, and do whatever they feel needs to be done to “win” their case. It is apparent that often they feel that they know who did it– they just need to muster the facts necessary for a conviction. They sometimes regard the law as an impediment to justice.

They almost never willingly admit a mistake, even when DNA analysis proves they were wrong.

Occasionally, it is clear, they manufacture the “facts”. An expert, for example, will testify that a fiber found in the suspect’s car exactly matches a fiber taken from the victim’s sweater. So how do you assess the real degree of similarity, and the real likelihood that these fibers could have matched fibers from almost anyone else’s sweater? The lab is not presented with five samples and five potential matching fragments of evidence, and then asked to identify which ones match. They are presented with a set of fibres from the suspects home or clothing, and a set of fibres found at the crime scene. Do they match, yes or no? If no matches are found, we’ll find more fibres, and then more. The lab technician knows that the police will be happier if a match is found.

A suspect’s car– or any car– is loaded with smells, particles, dust, fragments of things, scraps of paper, coffee stains, oil and grease, residues, maybe even bodily fluids. If you took thousands of samples of every substance in a any car, how hard would it be to find something– anything– that matches something that can be linked to a victim– any victim? I’ll bet it wouldn’t be that hard at all.  Look at the Azaria Chamberlain case.

The Supreme Court is right. We should demand very high standards of “expert” testimony, before allowing smooth-talking partisan professionals to try to bowl over a jury with analysis that might well be nothing more than “junk science”.

Random Notes:

Until the 1880’s, the commonly accepted “age of consent” in America was 11.

2011-06: in the case of Casey Anthony, the prosecution is actually presenting “evidence” that traces of the smell of a decomposing body can be detected and analyzed from the trunk of Ms. Anthony’s car. This has all the hallmarks of the good old fibre analysis presented at so many cases by discredited forensic “scientists” in the past.

I hope her defense attorney has the intelligence to ask the prosecution to produce evidence of the smells of hundreds of cars compared to the smell captured from Ms. Anthony’s car and then have the “expert” blindly identify which one had the body in it.