An article in the L.A. Times has this amusing lede:

Hillary Rodham Clinton may be short on delegates, money and time, but she faced an even more ominous and intractable impediment Wednesday: a growing consensus in the media that her bid for the Democratic presidential nomination is doomed.

Wow. A “growing consensus in the media.”

Wow.

You can’t fight City Hall, and you sure can’t fight a “growing consensus in the media.”

Except when that growing consensus is wrong, of course. Which happens an awful lot.

[Guest post by DRJ]

George Stephanoulos told ABC’s Charlie Gibson that he thinks Hillary Clinton is staying in the race because she believes there is a slim chance she can win. If she does quit, it will only be after wins in West Virginia or Kentucky.

He also thinks she would accept the VP slot “if it was offered in the right way.” He’s not sure Obama will offer.

— DRJ

[Guest post by DRJ]

Is sexually enticing speech on the internet a crime if it’s directed at minors? The Utah Supreme Court heard argument today on just that issue:

“Can the state convict someone of enticing a minor over the Internet based on their words alone? That issue was the subject of lively debate among justices of the Utah Supreme Court on Wednesday.

At issue is whether or not Utah’s Internet Enticement statute is unconstitutional by saying a person engaged in sexual speech over the Internet need only believe they are chatting with a minor in orded to be convicted.

“All you’re doing is criminalizing speech,” said attorney Ann Taliaferro. “There has to be something more.”

The Utah case concerns James Gallegos who was convicted and sentenced to a year in jail for enticing an adult Utah Internet Crimes agent posing as a 13-year-old girl on the internet. Gallegos chatted with the agent/girl twice online and described how he wanted to sexually touch her. They arranged a meeting but when Gallegos drove by the designated place, he sped off. Agents tracked him using his license number.

Gallegos claimed he just wanted to see what the person looked like:

“Gallegos claims he had never believed the person he was chatting with was a minor. At some point, Gallegos said he was convinced the person was a gay man posing as a girl because in the past he had arranged meetings with supposed females only to meet a man. The reason he showed up at the meeting site, was out of curiosity about this person.”

The statute requires that the suspect must believe the person they are chatting with is a minor. At one end of the spectrum was Gallego’s defense counsel who argued that internet chat is fantasy, not grounded in reality, and people can be anyone they want online. At the other end, a Justice suggested that if a party says they are a minor, “log off.”

Chief Justice Christine Durham noted that Gallegos went beyond sexual speech — he solicited a meeting with someone who claimed to be a minor and he showed up at the meeting place. She likened it to sexual solicitation of a 13-year-old on the street. However, another Justice was troubled by the law:

“Justice Michael Wilkins asked Gray if it was illegal for someone to have “cyber-sex” with someone claiming to be a minor. “Does the state consider cyber-sex to be sexual activity?” Wilkins asked. Gray said the state did not, but if the person solicited sex and believed it was a minor, that is what the law requires.

Wilkins wondered how the state can establish what a person believes short of having a full confession. He said he was “troubled” by the law and concerned about its constitutionality. In this case, Wilkins said it appeared all the state needed to do to convict someone was to go online, set up a meeting for sex and that is enough.

Typically, state agents will try to get the suspect to show up at a pre-arranged location and time in order to prove legal intent.”

Gallegos also complained that he was not allowed to call an expert witness whose testimony was offered to show that Gallegos is not attracted to young girls and is not a pedophile. The trial court ruled the evidence was not relevant but some justices indicated that if a crime involved intent, defendant should be allowed to challenge that with expert testimony.

— DRJ

[Guest post by DRJ]

Back in my college days, the biggest problems we had were hazing, hippies, protests, and pot. Greek life was especially tame, although it certainly had its share of hazing and alcohol. At today’s colleges, however, a few students have chosen more lucrative enterprises:

“The undercover officers started to appear at San Diego State fraternity parties about six months ago. They dressed like students, complained about their parents and professors, and talked freely and knowingly of things of great interest on campus: music, sex and drugs.

Soon they were accepted, with no questions asked. They were spotted at student hangouts on and off campus. They swapped cellphone numbers with other partygoers. They text-messaged their newfound friends.

The real students appeared to accept the pretend ones — most but not all of whom were men. On a campus of 34,000 students, blending into the crowd was not difficult. Neither was collecting evidence of drug dealing and drug use.

On Tuesday, authorities announced that 96 young men — including 75 students — had been arrested on a variety of drug charges as a result of Operation Sudden Fall, which infiltrated seven fraternities on Fraternity Row and Fraternity Circle. Officials said the name of the operation referred to the prospect of sudden death from drug usage.

The investigation involved marijuana, cocaine, methamphetamine and Ecstasy.”

One student asked officers if his arrest would hurt his chances to become a law enforcement officer some day.

The operation was planned following the drug overdose deaths of two students. Drug legalization groups objected to the use of DEA and police officers to target college students instead of large-scale drug traffickers, but the University’s President expressed no regret for letting undercover agents on campus.

— DRJ

[Guest post by DRJ]

Here we go again. Thomas DeFrank in the NY Daily News uses quotes from white Indiana voters to suggest that whites who won’t vote for Obama are either ignorant or racists:

“With Clinton posing alongside pioneering Indy speedster Sarah Fisher, there were almost no African-Americans to be seen. Many in the white, working-class crowd were simply not ready to back Barack Obama – for reasons that are disturbing.
***
Obama did manage to pull in many white voters, but still encountered similar sentiments from a man who refused to shake his hand at a diner in Greenwood, Ind.

“I can’t stand him,” the man said. “He’s a Muslim. He’s not even pro-American as far as I’m concerned.”

Such feelings leave Clinton and the Democratic Party in a tough spot. With the largest number of remaining delegates nowbeing party insiders, they have to decide if Obama can overcome enough of that antipathy – essentially deciding if enough working-class whites will back away from the black candidate, whether because of the false Muslim rumors, the Rev. Jeremiah Wright flap or old-fashioned racism.”

This might be a more convincing argument if whites were voting 9-to-1 for Hillary the way blacks are voting for Obama. It also sounds like the national media wants to shame whites into voting for Obama, which doesn’t strike me as a good way to win votes.

I found DeFrank’s speculation about Hillary far more interesting. He reports the Clintons believe a Democrat will win the Presidential election no matter how contentious the nomination process. That would certainly explain Hillary’s willingness to stay in the race until the convention, since an Obama win means this will be her only shot at the Presidency. As DeFrank says, there’s no downside for her.

— DRJ

[Guest post by DRJ]

Hillary Clinton vows to fight on after a narrow win in Indiana and a huge loss in North Carolina. Although she is behind in pledged delegates, votes and money, Clinton surrogates argue she is more electable and a known quantity compared to Obama.

A campaign aide revealed she loaned her campaign $6.4M in the past month.

You go, Hillary.

— DRJ

[Guest post by DRJ]

New research says conservatives are happier than liberals because they accept life has inequalities:

“Regardless of marital status, income or church attendance, right-wing individuals reported greater life satisfaction and well-being than left-wingers, the new study found. Conservatives also scored highest on measures of rationalization, which gauge a person’s tendency to justify, or explain away, inequalities.

The rationalization measure included statements such as: “It is not really that big a problem if some people have more of a chance in life than others,” and “This country would be better off if we worried less about how equal people are.”

To justify economic inequalities, a person could support the idea of meritocracy, in which people supposedly move up their economic status in society based on hard work and good performance. In that way, one’s social class attainment, whether upper, middle or lower, would be perceived as totally fair and justified.”

The authors said inequalities take a higher toll on liberals “apparently because liberals lack ideological rationalizations that would help them frame inequality in a positive (or at least neutral) light.”

Liberals may add this study to their list of examples of heartless conservatives but, if so, that’s unfortunate. It’s impossible to give everyone exactly the same benefits and opportunities. We do our best to treat everyone fairly and we work to improve how people are treated.

— DRJ

It might seem a little odd for me to vet an e-mail I am planning to send by publishing a draft of it on a public website that receives thousands of hits every day. But hey, odd is fun! And so I invite you to read this draft (yet unsent) of a letter to the authors of the recent L.A. Times article on DNA, cold hits, and statistics.

I’d like readers to review it before I send it because I am not a statistics expert, and although I consulted with more than one during the process of drafting this, I want to make sure I have made no mathematical or logical misstatements.

Here it is:

Mr. Felch and Ms. Dolan,

After discussions with numerous people with statistical expertise, I am reasonably confident (that is, as confident as a layman like myself can be) that your recent front-page article on DNA cold case statistics gravely misstated the meaning of the math you discuss.

Your article said:

Jurors were not told, however, the statistic that leading scientists consider the most significant: the probability that the database search had hit upon an innocent person.

In Puckett’s case, it was 1 in 3.

I don’t believe the math in question supports the statement that there was a “1 in 3” chance that “the database search had hit upon an innocent person” in selecting Puckett.

The starting point for my analysis was this post by Eugene Volokh, a UCLA law professor and blogger. Prof. Volokh agrees with me that your formulation is wrong. He justifies his argument with effective argumentation and examples; I commend his post to you. My e-mail to you (which I am blogging on my site) merely expands on Prof. Volokh’s argument as it relates to the article.

(To keep the discussion simple, I will assume there are no issues relating to data corruption or human error. I’ll also stick with the numbers used in your article: a random match probability of 1 in 1.1 million, and a database of 338,000.)

The logic behind the database adjustment was expressed in a report from the National Research Council as follows:

Recommendation 5.1 proposes multiplying the random-match probability (P) by the number of people in the database (N). If the person who left the evidence DNA was not in the database of felons, then the probability that at least one of the profiles in the database would also match the incriminating profile cannot exceed NP.

The clear working assumption here is that the database consists of “innocent” people who did not leave the DNA in the database.

This makes sense, at least in a hypothetical case where the jury is informed that the authorities came to suspect the defendant because of a database hit. There is a certain “what are the chances?!” quality of DNA evidence that presumes the defendant was under suspicion before the DNA comparison was done. In other words, if the defendant is before the jury because of a database hit, and the jury knows it, the jury may be “wowed” by the fact of the hit. But the impact of this “wow” factor is considerably lessened likely if the jury is told that, in a hypothetical search of a database of completely innocent people, there is a 1/3 chance of a hit.

Thus, it seems clear to me that the idea of the adjustment is to communicate to the jury the likelihood of a false positive, based on the assumption that the true donor of the incriminating profile is not in the database.

My understanding is bolstered by an e-mail I received from Prof. David Kaye, who served on the 1996 NRC committee that recommended the adjustment. In that e-mail, Prof. Kaye stated:

[T]he statisticians who favor an adjustment to the random-match probability are considering [the question:] What is the chance that a search of a database will turn up exactly one match when the source of the crime-scene DNA is someone who is unrelated to everyone in the database?

He restated the question in this way:

What is the chance that a database composed entirely of innocent people (with respect to [the] crime being investigated) will show a match?

Note that the fundamental assumption of the hypothetical is that everyone in the database is innocent. Then, and only then, can one use the adjusted figure recommended by the committees as a (very rough) approximation of the chances of a false positive.

If by contrast, you start with the assumption that you don’t know whether the suspect is in the database or not, then the 1/3 number tells you nothing about whether a single hit from the database is a hit to a) the true donor of the incriminating DNA or b) an innocent person who happens to share the same profile (i.e. a “false positive”).

It’s important to keep in mind that what we’re talking about here is the situation where a database search is conducted, and has resulted in only one hit. The question is: what can we say, statistically, about that one hit?

In the case where you don’t know whether the database contains the the true donor, or “guilty” person (speaking very loosely), the meaning of a single hit from that database is a function of the likelihood that the true donor is in the database — and (given that only one hit was received) the likelihood that nobody else with that profile is in the database.

If you don’t know whether the true donor (or “guilty” person) is in the database or not, the 1/3 number is merely an expression of the likelihood of a hit — any hit. It’s not an expression of the chances that any resultant hit is a hit to an “innocent” person.

Again, I am not a statistics expert, and (perhaps as a result) I don’t know whether it is possible to tell juries anything statistically meaningful about the likelihood that the person in front of them is innocent. (Neither does Prof. Volokh, for what it’s worth.) But I feel fairly confident that the 1/3 number is not an expression of the probability that the person sitting in front of jurors is “innocent.”

Thus, I believe that your article is wrong to say, in the statement quoted above, that “the probability that the database search had hit upon an innocent person” in Puckett’s case was “1 in 3.”

That is simply not so, I believe.

If I’m right, I think The Times needs to correct this misimpression. What’s more, I think any correction should be very prominent, given the extreme prominence of the error (or what I believe to be an error) on the front page of the paper’s Sunday edition.

I hope you will see your way clear to discussing these issues with knowledgeable experts. I also hope that you will issue an appropriate and prominent correction if, after reflection and consultation with experts, you believe I have correctly analyzed the issue.

I look forward to your response.

P.S. I should note that my argument does not address the fact that guilt is not automatic once it is determined that the suspect is the donor of the DNA at the crime scene, just as innocence is not automatic once it is determined that he is not the donor. I assume you are aware of the difference between source attribution and guilt, and left out an explanation of the difference for space reasons.

Nor does my argument address the fact that the 1/3 number is an approximation of an approximation. (Prof. Volokh’s post has more details on the relevant statistics.) I also presume you were aware of this, and believe that the 1/3 number is simply a conservative simplification of the more complex equation that Prof. Volokh sets forth in his post.

My argument has nothing to do with these relatively minor quibbles. One could argue that ignoring them is necessary to keep the issue straightforward and simple. My problem is that, these minor issues aside, the way you have expressed the meaning of the adjusted number is (I believe) so misleading as to be fairly termed an error.

Please let me know what you think. I remain humble on the issue because of my lack of expertise in the field.

One of my complaints about the recent L.A. Times article on DNA, cold hits, and statistics is that I believe it inadequately portrayed the extent of disagreement regarding the need for the statistical adjustment discussed in the article (multiplying a random match probability like 1 in 1.1 million by the size of a database like 338,000.) . I’ll once again show you the image of the front page to remind you how strongly the paper portrayed the adjustment as the product of a wide consensus among leading experts:

Yet, as I have previously noted, the L.A. Times‘s own expert mathematician Keith Devlin of Stanford says that “the relevant scientific community (in this case statisticians) have not yet reached consensus on how best to compute the reliability metric for a cold hit.” And Prof. David Kaye, who was on the 1996 committee that recommended the adjustment, actually told me that the contrary view is more widely accepted:

[The L.A. Times‘s] description portrays one approach to the issue as if it is the consensus in the scientific literature. It is not. There is disagreement about the need to adjust a random-match probability. Furthermore, if one counts the number of peer-reviewed articles on the subject, the dominant view is that adjustment is not necessary.

Jason Felch, one of the authors of the L.A. Times article, responded to this portion of my complaint, and authorized me to quote him:

That brings us to your second point: that we did not portray the full scientific debate in the article. You are right in saying that a debate persists among statisticians (as it does in most complex scientific questions.) The 1996 National Research Council and, after its dissolution, the FBI’s DNA Advisory Board carefully weighed the arguments of the various statistical camps — the Bayesians and frequentists, but also those who favor likelihood ratios or the first NRC’s approach, which defense attorneys are arguing for now and is more conservative that the NRCII’s adjustment. Both NRC and the DAB concluded the RMPxDATABASE approach was best for cold hit cases. In the forensic field, these two bodies are the source of authority on questions of science — The NRCII is referred to as the “bible” of forensic DNA. But their recommendations are not being followed. This is the point we make in the article, while acknowledging there is not unanimity of opinion.

For the courts, the question is: is there enough of a consensus on this issue that a generally accepted practice has emerged? If the answer is no, the law (Kelly-Frye here in California, Daubert in other states) holds that the evidence should not be presented in courts. So there’s a lot at stake in the question. Not surprisingly, many in the field argue that the issue is not a lack of consensus, but a debate among which of several accurate scientific approaches is more appropriate. So far, the courts have agreed. This is what the California Supreme Court will weight. We are likely to explore some of these complexities in our upcoming coverage of that case.

I’m not convinced that the paper “acknowledg[ed] there is not unanimity of opinion” is a way that was meaningful to readers. The article never even mentioned the entire Donnelly/Balding hypothesis that Prof. Kaye says constitutes the majority opinion of peer-reviewed articles. Readers were told only in passing, deep in the article, that the adjustment discussed in the article “has been widely but not universally embraced by scientists.” As for how the article portrayed general scientific acceptance of the adjustment, I refer you once again to the image of the front page above.

But while I might disagree with Mr. Felch, I thank him for his response.

P.S. I am working on a proposed e-mail to Mr. Felch that questions the article’s assertion that there was a “1 in 3” chance that “the database search had hit upon an innocent person” in selecting Puckett.