June 8, 2010

New study: Children of lesbians more competent

The growing acceptance of same-sex marriage -- now legal in 8 countries, 5 U.S. states, and among the Coquille Indians in Oregon -- demonstrates the rapid social and legal progress of lesbians and gay men. Yet a handful of expert witnesses are still testifying in court that sexual minority parents put children at risk for bad outcomes.

Experts must rely on science. So these antigay experts cite biased research and make strained inferences from supposed empirical evidence of higher rates of psychiatric problems, substance abuse, and relationship instability among sexual minorities as a group. Of course, it's apples and oranges, because those studies are not of parents. These self-described experts only get away with such testimony due to societal prejudice; imagine a scientist testifying for a ban on adoption by Native Hawaiians due to their relatively higher rates of illegal drug use than Asians as a group.

But a new study in the journal Pediatrics blows this sham pseudoscience out of the water. The first prospective, longitudinal study of planned lesbian families found that by adolescence the sons and daughters of lesbians had better psychological adjustment across the board than their demographically matched counterparts from a large normative sample of American youth.

At age 17, both boys and girls were rated significantly higher in social, academic, and total competence and significantly lower in social problems, rule-breaking, aggression, and externalizing behavioral problems.

Interestingly, although more than half of the co-parent couples separated during the time period of the study, this did not affect their children's psychological health. That finding contrasts with the negative impact of divorce on children in heterosexual families. The researchers theorize it may be due to the nature of shared child-rearing among separted lesbian mothers.

The authors theorize that one factor in the relatively superior adjustment of these children is that their parents use less corporal punishment and authoritarian power assertion than do heterosexual fathers:
Growing up in households with less power assertion and more parental involvement has been shown to be associated with healthier psychological adjustment. Also, adolescent boys who are close to their parents are less likely to engage in delinquent behavior.
The study followed 154 prospective mothers who volunteered beginning in 1986 to be followed from their children's conception to adulthood. Because of its prospective nature, findings were not skewed by overrepresentation of families who volunteered once their offspring were doing well. Although the sample was non-random, this was offset by a remarkably high retention rate of 93 percent. The study is ongoing.

These and related findings have significant implications for child custody and adoption cases in which experts testify that the sexuality of the parents is relevant under the "best interest of the child" standard. Respected child custody expert Jonathan Gould and his colleagues have argued that parental sexual orientation is irrelevant to this issue. Forensic psychologist William O'Donohue disagrees. But now, an expert who does raise parental sexuality as a potential negative can expect to be confronted with mounting evidence that -- far from being a liability -- having lesbian parents may actually confer some advantages to children.

Related resources:

Pediatrics has made the article available for free online (HERE). My article in the Journal of Forensic Psychology Practice summarizing the state of this research as of 2003 is: Practice Opportunities with an Emerging Family Form: The Planned Lesbian and Gay Family (Volume 3, Issue 3, pages 47-64).

Photo credit: Telegraph (UK); Hat tip: Ken Pope

June 4, 2010

Groundbreaking study of sex offender life courses

Challenge to actuarials: 4 distinct trajectories ID'd

Actuarial tools to predict offenders' future risk are all the rage. They provide a veneer of science in that on average their simple formulas work somewhat better than the flip of a coin. But a bit of sleight of hand is involved. They work only by lumping everyone together, making the vast differences among individuals with similar risk scores magically disappear. Thus, they say little about the risk of the specific offender standing in court awaiting judgment.

In addition to masking differences between individuals, actuarial risk assessment tools such as the Static-99 and the MnSOST-R ignore changes within an individual over time. As offenders age, they tend to rack up more arrests, which are scored as historical risk factors that elevate risk. But paradoxically, as men reach their 40s their days of crime are numbered. Many actuarially minded evaluators show a remarkable ignorance of the robust criminological literature on desistance, viewing sex offenders through an insular and mechanistic lens of history as destiny.

In the first study to directly challenge these actuarial fallacies by examining the offending trajectories of adult sex offenders from early adolescence to adulthood, a group of Canadian criminologists has identified four distinct offending trajectories, and in the process found a couple of surprises.

The four trajectories, identified by Patrick Lussier of Simon Fraser University and his colleagues through a longitudinal, retrospective study of 250 convicted sex offenders in a federal prison, were -- in order from most to least prevalent:
  • Very-low rate (56%): The most common trajectory involves a very low rate of offending over the time period examined, from ages 12 to 35. Most of these men were child molesters. Their offending appeared to be transitory and limited.
  • Low-rate desistors (26%): This group followed the age-crime curve identified by criminologists such as Sampson and Laub and Moffitt for offenders in general. This trajectory takes off gradually in adolescence, peaks in young adulthood, and gradually declines in the mid-30s. Offenders begin with general criminal activity and escalate over time to more serious crimes, including sex offending. Paradoxically, sex offending begins just as their overall criminal activity is slowing down.
  • Late bloomers (10%): This group is largely neglected in scientific literature about sex offending, according to the researchers. Rather than following the typical age-crime curve, late bloomers start their offending in adulthood, and gradually increase into their mid-30s. Like the low-rate desistors, this group progresses from nonsexual, nonviolent crimes to sex crimes. Many of these offenders sexually assault adolescent females.
  • High-rate chronics (8%): This group somewhat matches that known to criminologists as the "life-course persistent" group. The smallest of the four groups, it is also the most criminally active. These offenders start out as juvenile delinquents and offend frequently as adults, with sex offenses as just one component of general criminality. Most of the sex offenders in this group raped adult women.
These findings have a notable implication for risk assessment with juveniles. Despite their highly divergent rates of crime and desistance, three out of the four groups are not distinguishable during adolescence. As Frank DiCataldo explains in his new book, Perversion of Youth, the smart gambler will place bets that any random juvenile sex offender will NOT go on to become a chronic sex offender as an adult.

Lussier and his colleagues are critical of the actuarial tools for failing to capture the desistance process:
Some individuals might be considered high-risk offenders when their criminal activity is actually in the desistance process. This might be particularly true for the low-rate desistors and the high-rate chronics. Others, such as the late-bloomers, might be underestimated by actuarial tools considering that their criminal involvement started later and did not accumulate the risk factors included in the actuarial tools, in spite of the fact that their offending is accelerating…. We are left wondering how current actuarial risk assessment tools can account for the diversity of offending trajectories of sex offenders and the dynamic aspect of their offending over [the] life course.
The researchers report that they will study the predictive validity of their model in a future study. They also recommend further studies to extend the age range past the mid-30s, to better understand the various trajectories over the entire life course.

The study is: "Criminal trajectories of adult sex offenders and the age effect: Examining the dynamic aspect of offending in adulthood," by Patrick Lussier, Stacy Tzoumakis, Jesse Cale, and Joanne Amirault, in the current issue of the International Criminal Justice Review.

Other newly published articles on the actuarial controversy:

Campbell, T.W., & DeClue, G. (2010). Flying Blind with Naked Factors: Problems and Pitfalls in Adjusted-Actuarial Sex-Offender Risk Assessment. Open Access Journal of Forensic Psychology. Available ONLINE.
ABSTRACT: Actuarial instruments are typically the centerpieces of evaluations pursuant to civil commitment statutes for sex offenders. Almost as frequently as they rely on actuarial instruments, evaluators adjust actuarial data via weighing additional variables that are (presumably) correlated with recidivism. Typically, however, such variables are only weakly related to reoffending. This article reviews many problems and pitfalls undermining Adjusted Actuarial Assessment (AAA) and reports data demonstrating how ill advised this procedure is. Publicly available data do not support a claim in a recent meta-analysis (Hanson and Morton-Bourgon, 2009, p. 7), "For all three measures, for all types of raters, and for all outcomes, the adjusted scores showed lower predictive accuracy than did the unadjusted actuarial scores." Based on available data, at its best, AAA neither increases nor decreases the accuracy of actuarial classification. At its worst, AAA dilutes actuarial accuracy.
Craig, L.A., & Beech, A.R. (2010). Towards a guide to best practice in conducting actuarial risk assessments with sex offenders. Aggression and Violent Behavior, 15, 278-293.
ABSTRACT: Assessing the risk of further offending behavior by adult sexual perpetrators is highly relevant and important to professionals involved in public protection. Although recent progress in assessing risk in sexual offenders has established validity of actuarial measures, there continues to be some debate about application of these instruments. Increasingly forensic practitioners are being requested to give expert witness evidence in formal settings where actuarial risk estimates are being examined. This is true in the Sexually Violent Predator (SVP) hearings in the United States and the Parole Board Hearings in the United Kingdom. It is important therefore for practitioners using actuarial scales in adversarial settings to have a thorough understanding of methodological limitations of the technology and possible errors and inaccuracies of reporting actuarial risk estimates in individual cases. The aim of this paper is to summarize strengths and weaknesses of actuarial risk data, and to contribute to developing guidance on best practice when using actuarial measures in adversarial settings. This paper is organized into six areas: (1) Actuarial scales in practice; (2) Understanding risk prediction concepts; (3) Factors known to affect actuarial estimates; (4) Can we use group data to assess risk in individual cases; (5) Choosing which actuarial risk measure to use; and (6) Reporting actuarial risk estimates. It is hoped this paper goes some way to establishing guidance on the best practice of actuarial scales and associated limitations.

June 1, 2010

More coverage of psychopathy censorship controversy

The controversy over Robert Hare's attempt to block publication of a peer-reviewed article critical of his psychopathy construct is getting more attention since Sunday's blog post. Among the online coverage:
  • Intellectual Competence and the Death Penalty gives it a nod, as does Kevin Cole, Dean at the University of San Diego School of Law, at his CrimProf blog.
  • And they're even blogging about it over in Gothenburg, Sweden!
Overwhelmingly, opinion is that Dr. Hare shot himself in the foot by threatening legal action against the researchers and the journal. Hopefully, this debacle will serve as a cautionary tale for others whose research undergoes critical scrutiny due to forensic or other public-policy implications.

Federal judge rules against fMRI lie detector

The widely awaited ruling on the admissibility in court of fMRI for lie detection purposes has just come down, and it's bad news for proponents of the novel brain-scanning technology. In a potentially landmark opinion, a federal magistrate ruled yesterday that the technology is unreliable and has not been accepted by the scientific community. The 39-page opinion followed a closely watched evidentiary hearing in Tennessee (see my previous post HERE).

Detailed coverage of testimony at the Daubert evidentiary hearing can be found HERE. As reported by Science Insider, Judge Tu Pham held that the novel scientific technique has been subjected to testing and peer review, but is not general accepted by scientists nor are its error rates established. The judge's ruling also highlighted the distinction between laboratory research and performance in real-world settings.

Lorne Semrau, a psychiatrist facing trial on multiple counts of Medicare and Medicaid fraud, had sought to introduce his fMRI results as evidence of lack of fraudulent intent.

The full ruling is online HERE.

May 30, 2010

Psychopathy guru blocks critical article

Will case affect credibility of PCL-R test in court?

Despite recent evidence that scores on the Psychopathy Checklist-Revised (PCL-R) vary widely in adversarial legal contexts depending on which party retained the evaluator, the test has become increasingly popular in forensic work. In Texas, indeed, Sexually Violent Predator (SVP) evaluators are required by statute to measure psychopathy; almost all use this test. It is not surprising that prosecutors find the PCL-R particularly attractive: Evidence of high psychopathy has a powerfully prejudicial impact on jurors deciding whether a capital case defendant or a convicted sex offender is at high risk for bad conduct in the future.

But a current effort by the instrument's author, Robert Hare, to suppress publication of a critical article in a leading scientific journal may paradoxically reduce the credibility of the construct of psychopathy in forensic contexts.

That's the opinion of two psychology-law leaders, psychologist Norman Poythress and attorney John Petrila of the University of South Florida (two authors of a leading forensic psychology text, Psychological Evaluations for the Courts), in a critical analysis of Dr. Hare's threat to sue the journal Psychological Assessment. The contested article, "Is Criminal Behavior a Central Component of Psychopathy? Conceptual Directions for Resolving the Debate," is authored by prominent scholars Jennifer Skeem of UC Irvine and David Cooke of Glasgow University. The study remains unpublished.

"[T]he threat of litigation constitutes a serious threat to academic freedom and potentially to scientific progress," write Poythress and Petrila in the current issue of the International Journal of Forensic Mental Health. "Academic freedom rests on the premise that advances in science can only occur if scholars are permitted to pursue free competition among ideas. This assumes that scholars have the liberty to do their work free from limitations imposed by political or religious pressure or by economic reprisals."

According to Poythress and Petrila, after the critical article passed the peer-review process and was accepted for publication, Dr. Hare's lawyer sent a letter to the authors and the journal stating that Dr. Hare and his company would "have no choice but to seek financial damages from your publication and from the authors of the article, as well as a public retraction of the article" if it was published. The letter claimed that Skeem and Cooke's paper was "fraught with misrepresentations and other problems and a completely inaccurate summary of what amounts to [Hare's] life's work" and "deliberately fabricated or altered quotes of Dr. Hare, and substantially altered the sense of what Dr. Hare said in his previous publications."

In general, defamation claims must prove that a defendant made a false and defamatory statement that harmed the plaintiff's reputation. Truth is an absolute defense. Critical opinions are also protected from defamation actions, as are "fair comments" on matters of public interest.

In this case, the contents of Skeem and Cooke's contested article have not been made public. However, it is hard to see how critical analysis of a construct that is enjoying such unprecedented popularity and real-world impact would NOT be of public interest.

Poythress and Petrila express concern that defamation claims against opposing researchers, while traditionally rare, may be becoming more common, leading to a potentially chilling effect on both individual researchers and the broader scientific community. Like so-called SLAPPS -- Strategic Lawsuits Against Public Participation -- used by corporations and other special interest groups to impede public participation, even meritless defamation lawsuits extract heavy penalties in terms of lost time and money and emotional distress.

Judges have been critical of pretextual deployment of defamation lawsuits, Poythress and Petrila report; a judge in one case warned that "plaintiffs cannot, simply by filing suit and crying 'character assassination!,' silence those who hold divergent views, no matter how adverse those views may be to plaintiffs' interests. Scientific controversies must be settled by the methods of science rather than by the methods of litigation."

Potential negative effects of defamation threats against scientific researchers include:
  1. Researchers avoid conducting critical research out of fear of lawsuits.
  2. Academics decline to serve as volunteer peer reviewers for academic journals due to loss of anonymity in defamation suits.
  3. Journal editors self-censor on controversial topics.
As Poythress and Petrila conclude:

Because publication of the article by Professors Skeem and Cooke has effectively been long delayed, if not ultimately suppressed, one clear impact of this threat to sue is that researchers who may have been willing to investigate alternative models of psychopathy that might have been derived from the Skeem and Cooke article are not able to do so, simply because the article is unavailable. Because science progresses, in part, both by confirming viable models and disconfirming nonviable ones, the suppression of information relevant to constructing candidate models for empirical evaluation can be viewed as impeding the progress of science….

[I]t seems clear from our review that such threats strike at the heart of the peer review process, may have a chilling effect on the values at the core of academic freedom, and may potentially impede the scientific testing of various theories, models and products.
In our view it is far better to debate such matters in peer review journals rather than cut off debate through threats of litigation.
In court, meanwhile, the effects of Dr. Hare's threat may prove paradoxical. Attorneys whose clients could be prejudiced by introduction of the Psychopathy Checklist may be able to discredit the instrument by pointing to the suppression of critical literature about the underlying construct of psychopathy.

POSTSCRIPT: Just hours after I posted this, alert readers advised me that: (1) Dr. Skeem discusses the as-yet-unpublished article in her 2009 book, Psychological Science in the Courtroom: Consensus and Controversy, co-authored by Kevin Douglas and Scott O. Lilienfeld (page 179 in the Google book view is HERE), and (2) according to Dr. Hare's website, he has a response in press (which, ironically, cites the Skeem and Cooke article as being published last year).

The full article is: "PCL-R Psychopathy: Threats to Sue, Peer Review, and Potential Implications for Science and Law. A Commentary," by Norman Poythress and John P. Petrila, in the current issue of the International Journal of Forensic Mental Health. The abstract if available HERE; the full article requires a subscription.

Dr. Hare's response is: "The role of antisociality in the psychopathy construct: Comment on Skeem & Cooke (2009)."
Hare, R. D., & Neumann, C. S. (in press). Psychological Assessment.

Of related interest:

  • "The Dark Side of Peer Review," by Stephen D. Hart, also in the current issue of the International Journal of Forensic Mental Health (abstract HERE)

  • "Does interrater (dis)agreement on Psychopathy Checklist scores in Sexually Violent Predator trials suggest partisan allegiance in forensic evaluations?" by Murrie, D.C., Boccaccini, M.T., Johnson, J.T., & Janke, C. (2008). Law & Human Behavior, 32, 352-362 (abstract HERE)

May 27, 2010

Sex offender fallout hitting unrelated laws

Flawed idea would penalize indigent mentally ill

The U.S. state of Delaware marks the letter "Y" on the driver's licenses of sex offenders. Louisiana emblazons the words "SEX OFFENDER." Here in California, a politician running for state attorney general is trying to bootstrap a victory in next week's primary election with a copycat proposal.

Imagine the shame and humiliation when the young store clerk asks for your ID to verify your credit card signature. It's just one more brick in the wall of internal banishment, which -- as law professor Corey Rayburn Yung has pointed out -- is radically changing the face of American culture.

Of course, shaming and banishment are nothing compared with the murders driven by this hysterical and counterproductive scapegoating. Take the unfortunate Florida man who was beaten to death with a baseball bat in his own home by two men who thought he was a convicted sex offender. As it turns out, the elderly gentleman had no criminal record whatsoever; he just happened to share the same name as a sex offender.

Some may dismiss that murder as the rash act of a couple of drunken hooligans. But, as I blogged about back in 2007, such vigilanteism is not uncommon. It is fueled by the rhetoric of our presumably rational leaders -- politicians, policy makers, even mental health experts. In my primary election voter's guide, almost every candidate down to the dogcatcher is promising to make the world safer from sex criminals like Phillip Garrido.

The current freneticism is linked to the case of John Gardner, who raped and murdered teens Chelsea King and Amber Dubois in San Diego. As I noted in my April 3 post on that case, politicians would rather point fingers than accept the limitations of the science of prediction. In a plea bargain that saved his life, Gardner has been sentenced to life in prison without the possibility of parole. His fate is sealed, but the forensic repercussions are just beginning. First up, politicians have approved a $250,000 probe aimed at uncovering flaws in the state Department of Mental Health's practices of screening paroling prisoners to detect sexually violent predators.

Dangerous expansion proposed for MDO law

An especially troublesome piece of forensic fallout from the Gardner case is a proposal by the Sex Offender Management Board (SOMB), created by California's legislature in 2006 to systematize oversight of the state's sex offenders. The Board has issued a report, at the governor's request, that contains a shocking claim and recommendation:

"Changes to the Mentally Disordered Offender (MDO) Commitment Law Might Have Permitted Gardner to Be Committed to a Mental Hospital And Prevented Further Crimes"

Wow! What does the MDO law have to do with sex offenders?! For readers who are not familiar with it, California's Mentally Disordered Offender (MDO) law was enacted in 1986 to protect the public from prisoners who upon release would pose a substantial danger of physical harm to others due to a severe mental disorder. In this case, "severe mental disorder" means just what it sounds like -- a genuine psychiatric disorder (most typically of psychotic proportions) that significantly impairs functioning.

Apparently, Gardner was flagged as a possible candidate for MDO commitment because he received some mental health treatment while in prison. But he was found not to meet the criteria for involuntary hospitalization under that law. As the forensic expert who evaluated him before his trial in 2000 had noted, he had no psychotic disorder; he was "simply a bad guy who is inordinately interested in young girls."
Snippet from forensic report on Gardner, courtesy San Diego Union-Tribune

News accounts have stated that the two MDO evaluators (one from the Department of Corrections and the other from the Department of Mental Health) differed as to whether Gardner had a severe mental disorder. In such cases, a prisoner is not hospitalized unless two independent evaluators from the Board of Prison Terms agree that he meets the criteria, and in Gardner's case this second pair of evaluators also reportedly split.

Based on its skimpy information (they admitted that they had not verified the news reports about Gardner's MDO evaluations), the Board is recommending two radical changes to existing law:
  • Amend the MDO law (and remember, this law does NOT target sex offenders!) so that a prisoner is involuntarily hospitalized when a second set of evaluators comes back with a split opinion.
  • Eliminate the current right of people committed under the MDO law to an annual review by the courts; "the MDO commitment system should mirror the system which now commits sexually violent predators (SVP's) for an indeterminate term."
Double Wow! Talk about increasing the "false positive" problem exponentially!

Remember, the MDO law was not designed for sex offenders. It is meant to civilly incapacitate paroling prisoners with bona fide psychiatric disorders that make them violent. Yet these folks in the sex offender arena want to fiddle with this law in order to remove the meager procedural safeguards that protect the mentally ill from indefinite detention.

Given its timing, this proposal may not be as illogical as it might superficially appear. It comes just in time for an upcoming court hearing on whether the state can continue to handle civilly committed sex offenders differently than other civilly committed ex-prisoners.

On Jan. 28, in response to a challenge by a civilly detained sex offender named Richard McKee, the California Supreme Court ruled that the state "has not yet carried its burden of showing why SVP's, but not any other ex-felons subject to civil commitment, such as mentally disordered offenders, are subject to indefinite commitment" [my emphasis]. The state's top court sent the case back to the original trial court to give the government "the opportunity to justify the differential treatment in accord with established equal protection principles." That hearing, coincidentally enough, is pending in San Diego Superior Court.

Wouldn't it be convenient if the state changed the procedure for other civilly committed ex-felons to treat them similarly to sex offenders, just in time for the McKee hearing? Voila -- problem solved!

Is the current Mentally Disorder Law too lenient?

Consider this scenario:

"Josiah" has a chronic psychosis. He hears voices and is religiously preoccupied. Although normally peaceable, he had one bad day back in the 1990s, during which he raved at passing cars and even hurled a few small rocks. Fortunately, no one was injured. Josiah passively obeyed the commands of passersby to lie on the ground and wait for police.

Josiah was arrested. He pleaded guilty to a felony charge and went to prison. After some time, he paroled from prison. Despite continuing homelessness and mental illness, he did not engage in any further violence. However, he was briefly returned to prison for a minor, nonviolent parole violation. Upon his re-release, he had the misfortune of being evaluated by MDO Evaluator X, who has a higher-than-average rate of "positive" opinions. Dr. X opined that Josiah posed a substantial risk of physical harm to others by reason of his chronic psychosis.

Dr. X's counterpart at the Department of Mental Health, Dr. Y, disagreed. He did not believe Josiah was dangerous, because he lacked any pattern of violent conduct. No matter. On the basis of only one psychologist's opinion, Josiah was whisked off to the state hospital. (Contrary to the impression left by the SOMB report that two additional tie-breakers are required when the initial two evaluators disagree, a second pair of evaluations is only required when evaluators differ on certain of the six criteria.)

Although he was well behaved and never assaultive, in the hospital Josiah remained religiously preoccupied, carrying his Bible everywhere and reading from it incessantly. Based on his religiosity and his rejection of psychotropic medications, hospital clinicians believed he remained dangerous, and opposed his discharge. So, he languished in the hospital for seven years. Finally, an attorney effectively challenged the state's claim of dangerousness, and a judge ordered Josiah released. He was 57 years old.

Under the current MDO law, people like Josiah can get trapped in the state hospital system. Josiah is not a sex offender, and -- unlike Gardner -- most sex offenders in prison are not even eligible to be screened under the current Mentally Disordered Offender law. Yet now, because of an isolated but highly publicized crime, along comes a proposal that would penalize mentally ill prisoners, most of whom -- like Josiah -- are poor people without the financial resources to stand up for their rights.

Time and time again, here's the way the story goes:
  1. An exceedingly rare but highly troublesome event occurs.
  2. A knee-jerk scramble ensues to find the cause and affix blame.
  3. Existing laws are impulsively altered.
  4. Unintended consequences ensue, most of them harmful.
I'm sure the SOMB felt under the gun to come up with something, since the governor was asking. But the MDO law is working just fine to do what it is supposed to do -- protect the public from severely mentally ill offenders who are dangerous. If anything, the system could use more safeguards against false positives, not fewer protections for mentally ill people like Josiah. If the law is twisted into some kind of an SVP-Lite, it will encourage misuse of diagnosis and treatment in the service of pretextual goals. And that will be sad.

It's too bad the SOMB members don't just stand up to the governor and legislature, and admit that the emperor has no clothes: Screenings are not magic. They will never be capable of predicting the future with 100 percent certainty, and eliminating all potential risk.

The false positives dilemma

When something goes wrong, politicians look for an easy fix, no matter how impractical, meaningless, or even harmful it may ultimately prove to be. As an Associated Press report noted in reference to the driver's license idea, "It's unclear how the measure might have helped Gardner's victims."

So true. Similarly, critics who claim the parole screening process was faulty are denying the unfortunate reality that even the most rigorous screening would not have saved Gardner's victims, because Gardner had no red flags. Paroled in 2005 from a six-year prison term for two counts of lewd and lascivious acts with a 13-year-old acquaintance, he looked like a garden-variety sex offender, one of many tens of thousands in California alone. He didn't come close to meeting the criteria for involuntary commitment as a sexually violent predator.
Gardner was a "false negative," someone who looked low risk but was not. Unfortunately, to eliminate all false negatives (called "Type II errors" by statisticians), one would have to vastly increase the rate of "false positives," or Type I errors, in which people are identified as at high risk when they really are not. In other words, if you reduce the risk of one type of error, you increase the risk of the other. And since the overwhelming majority of convicted sex offenders are never apprehended for another sex crime, any imperfect system geared toward identifying the small minority who will reoffend will wrongly flag many more who will not. (Most sex offenses are committed by men who have never before been apprehended, so they are not affected one way or the other by such identification efforts.)

Preventively detaining literally hundreds of thousands of aggregately low-risk men based on what a few of them might (or might not) do in the future would be unconstitutional. And on a practical level, it would be fiscally impossible. Ironically, Kansas -- the state whose pioneering sexually violent predator law withstood a constitutional challenge that paved the way for similar laws in other states -- recently suspended its SVP screenings because the process had become too costly. Strapped for cash, Kansas Department of Corrections officials decided to save $22,500 a month by stopping all psychological evaluations of paroling sex offenders. (They also closed four prisons and two boot camps and curtailed programs for offenders.)

I've said it before, but it merits repeating: Random danger is an unavoidable part of life. Sometimes, despite all of our efforts at public protection, bad stuff will still happen.

The San Diego Union-Tribune has numerous source documents on the Gardner case available online.

Graphics credits: (1) "Bogeyman" by faedrake (Creative Commons license);
(2) Type I and II errors is courtesy Tim Wilson ("Gilligan on Data" blog);
(3) "Behind the Bars" from Squibs of California, public domain (courtesy of
Indiamos)