Just as I feared, those misleading L.A. Times articles on DNA, cold hits, and statistics are starting to have an effect in the courtroom.
In May, the L.A. Times ran a front-page DNA article that completely botched the statistics on “cold hit” cases, falsely telling people (on Page One of the Sunday paper) that the odds of a particular convicted defendant being innocent were actually 1 in 3. The paper had absolutely no basis to make this statement the way they phrased it. I called them on it, as did Eugene Volokh. But the reporters and editors stubbornly refused to correct the error.
Then in July, the paper ran another Page One Sunday blockbuster, telling readers on the front page that a researcher had run searches in an Arizona DNA database that revealed “dozens” of matches, “each seeming to defy impossible odds.” Only on page A20 were readers told that most of these Incredibly Unexpected Matches were, in fact, “to be expected statistically” because each sample was matched to every other sample in the database — exponentially increasing the total number of comparisons, and “greatly increasing the odds” of finding a match. (There was a discrepancy between the expected number of matches and the reality, but this discrepancy was not anywhere as stunning as suggested on Page One. According to one researcher, statistics suggested there would be about 100 matches out of the 2 billion comparisons done in the Arizona database. In reality, there were actually 144 matches, instead of the expected 100.)
Even educated people got confused reading these articles. This can be explained, in part, by the fact that statistics is a very complicated subject. But part of the explanation lies in the articles’ overly dramatic presentation, coupled with their often misleading and sometimes flatly false statements concerning the relevant statistics.
I suspected that most educated people who trust the paper came away with only a vague notion of the math involved — but with a firm impression that There Is Something Wrong With DNA and that Jurors Are Being Lied To. I worried that jury verdicts in Los Angeles would be affected.
It’s starting to happen. These irresponsible articles have begun to bear fruit.
My wife tells me a very distressing story about a case recently tried in a courthouse in this County in which the defendant was charged with sexually assaulting a woman in her eighties. He was accused of scamming his way into her house and forcibly orally copulating her. He was prosecuted almost entirely on the basis of a cold hit. (There were, in fact, cold hits to the same DNA profile from samples taken from two other sexually assaulted elderly women. But the jury didn’t hear about those other sexual assaults. One of the other sexually assaulted women had died by the time of trial. The other refused to testify — and under state law could not be forced to.)
When the jury came back with a verdict, everyone expected that the defendant would be found guilty. After all, the DNA had not been degraded. After the cold hit, a sample of the defendant’s DNA was compared to the evidence sample and matched at all 13 loci. My wife doesn’t know the exact random match probability, but she believes it was 1 in several trillion (if not more). I am unaware of any proven case in the history of DNA analysis where two samples matched at 13 loci and turned out to be two different people (with the obvious exception of identical twins, of course). (The most recent L.A. Times article darkly hinted at such a possibility, but it has never been shown to happen, as far as I am aware.)
The jury came back not guilty.
The accused man would be walking the streets — except that he is being held on an immigration hold. (But that’s another story.)
And the foreman of the jury told the D.A. afterwards that he felt the D.A. had failed to prove the case with DNA, “in light of recent controversies about DNA.” (Controversies that had been specifically ruled inadmissible by the judge.) He didn’t mention the L.A. Times specifically, but he was a local law professor. It stands to reason that he likely followed the front-page articles above with some degree of interest.
I wasn’t there, and I don’t know precisely what the evidence was. But I’m hearing that the judge was shocked, and that at least one well-respected defense attorney in the courthouse feels that justice was not done.
If you want to know why I get so upset at these articles and their sloppy and misleading language, this is why.
Actual dangerous people are going to end up walking the streets because the editors and reporters at the L.A. Times feel a compulsion to overdramatize their DNA findings, and occasionally misstate the statistics in seriously meaningful ways.
It is, of course, incredibly unlikely that the reporters and editors involved in putting these articles together will ever be directly affected by verdicts like the one I just told you about. Even in the topsy-turvy statistical world of the Los Angeles Times, where impossible odds are portrayed as commonplace, it is still incredibly unlikely that the man just freed by this verdict will sexually assault, say, the elderly mother of one of the editors or reporters.
But I’d be willing to bet he’ll assault someone‘s mom.
Are you proud, L.A. Times reporters? Are you happy to see that you’re Making a Difference?
Good. Hey, guys, I might eventually have an even better story for you. If this guy sexually assaults another elderly lady, I’ll try to get you an exclusive interview with her.
Sound good? Great! Hey, I understand. It’s all about the story.