MA- Defense attorney: Few factors reveal who will offend again

What they fail to say is, that the Static-99 does not predict anything if not used on offenders who have already committed multiple offenses. The Static-99 factors have been brought into question in court and held unreliable.
3-3-2008 Massachusetts:

There is scant scientific evidence available that can predict whether a sex offender will attack again, said a defense attorney who has helped free dozens of men who were civilly committed to the Massachusetts Treament Center in Bridgewater.

“I disagree with the notion that you should be able to put someone away, segregate them from the public for something that you think they are going to do if for no other reason than that we are not very good at prediction,” said attorney John Swomley. “We are putting lots of innocent people away for life without any basis for doing so.”

A Bay State Superior Court judge, Richard T. Moses, has faced withering criticism over the release of three sexual criminals accused of re-offending in recent weeks. Swomley said all but one of his clients have not re-offended, and that judges, juries and others have few truly reliable tools for anticipating recidivism.

The most credible tool for predicting whether a sex offender will attack again is an actuary instrument called the Static-99. The scale, developed by Canadian researcher R. Karl Hanson, takes into account prior sex offenses, sentencing dates, convictions for non-sexual violence, whether the victims were strangers, male, non-family members and other factors.

Offenders are scored on a numerical scale, with people scoring a 1 being the least likely to re-offend. People at 6 or higher on the test re-offend at a rate of 52.1 percent after 15 years in the community, according to the scale.

“This is really the only way you can pin prediction to anything that is scientific. Otherwise it is just tea-leaf reading, flipping coins and total clinical judgment, which has been determined to have no prediciative value at all,” Swomley said. ..more.. by Laura Crimaldi


Chart: The Static 99 table | The scoring system

Consider the following from a prior court case:

§ 9:42 Actuarial procedures—Cross-examining the static-99

1. The Static-99 is a 10-item actuarial instrument designed for assessing the recidivism risk of previously convicted sexual offenders — Correct?

2. The Static-99 combines an actuarial procedure previously developed in Great Britain, the Structured Anchored Clinical Judgment (SACJ), with the Rapid Risk Assessment for Sex Offense Recidivism (the RRASOR) — Correct?

3. The developers of the Static-99, Hanson and Thornton, characterize it as "… this year's version of a work in progress" — Correct?

4. "… this year's version of a work in progress" indicates there are various revisions anticipated for the Static-99 — Correct?

5. And if future revisions of the Static-99 are inevitable, then the Static-99 amounts to an experimental procedure — Correct?

6. And if the Static-99 is an experimental procedure - subject to future revisions - it cannot to be generally accepted by your professional community — Correct?

7. The developers of the Static-99, Hanson and Thornton, also report:
[ read ]

"Static-99 does not claim to be comprehensive, for it neglects whole categories of potentially relevant variables (e.g., dynamic factors)."— Correct?

8. If the Static-99 does not claim to be comprehensive, because of the variables it neglects, this consideration further demonstrates that the Static-99 is an experimental procedure — Correct?

9. Static-99 scores are translated as falling into one of four risk categories:
(1) Low, (2) Medium-Low, (3) Medium-High, and (4) High. — Correct?

10. Commenting on these risk levels, Hanson and Thornton report:
[ read ]

Although Static-99 can meaningfully differentiate between sex offenders with higher or lower probabilities of recidivism, the labels used to describe the various risk levels (low, medium-low, medium-high, high) do not reflect any absolute standard of risk.

Now my question: If the Static-99 risk level labels do not reflect any absolute standard of risk, your using those labels could mislead and misinform this court — Correct?

11. Validity data for the Static-99 were obtained from Canadian and United Kingdom populations — Correct?

12. And because the validity data for the Static-99 were obtained from Canadian and UK populations, we do not know to what extent those data are applicable my client in this particular case — Correct?

13. The validity data reported for the Static-99 are expressed in terms of "Receiver Operating Characteristic" (ROC) values —Correct?

14. Can you define for this court - in understandable terms - what a "Receiver Operating Characteristic" is?

[Surprising as it may seem, most professionals will be unable to answer this question]

15. Would you agree with the following explanation of the "Receiver Operating Characteristic" ?
[ read ]

In the instance of two randomly selected offenders (one a recidivist and the other a non-recidivist), ROC values indicate the probability that the recidivist scores higher on the Static-99 than the non-recidivist.

16. The ROC value reported for the Static-99 is .71 — Correct?

17. Therefore, the chances are 71 out of a 100, that the Static-99 score of a randomly selected recidivist exceeds the score of an randomly selected non-recidivist — Correct?

18. Can you explain to the judge [or jury] how that information can be used for decision-making in this case?

19. In other words, Receiver Operating Characteristic values are not applied in a simple, straightforward manner to this case — Correct?

20. The title page of the previously cited unpublished paper reporting on the Static-99 contains the following disclaimer:
[ read ]

The risk assessment procedures contained in this report, including Static-99 have been developed by the authors in the course of their duties. Anyone choosing to use or adopt the risk assessment procedures, including Static-99, in any way, does so on the sole basis of their responsibility to judge their suitability for their own specific purposes. The Department of the Solicitor General and Her Majesty's Prison Service, London, their employees, agents, servants, and the authors neither assume nor accept any responsibility or legal liability for any injury or damages whatsoever resulting from the use of the risk assessment procedures and Static-99.

Now my question: This disclaimer is less than a ringing endorsement of the Static-99 — Correct?

21. This disclaimer seems to be advising professionals - You assume an unknown level of professional risk when using the Static-99 — Correct?

22. Despite Testing standard 6.1, there is no commercially available manual for the Static-99 — Correct?

23. And the unavailability of a manual can compromise the inter-rater reliability for an instrument such as the Static-99 — Correct?

24. You cannot cite any inter-rater reliability data for the Static-99 published in a peer-reviewed journal — Correct?

25. You have not published any validity data in a peer-reviewed journal supporting the use of the Static-99 — Correct?

26. You cannot cite any validity data published in a peer-reviewed journal supporting the use of the Static-99 — Correct?

27. You cannot cite any data, identifying the levels of sensitivity for the Static-99, published in a peer-reviewed journal — Correct?

28. You cannot cite any data, identifying the levels of specificity for the Static-99, published in a peer-reviewed journal — Correct?

29. You cannot cite any data, identifying the frequency of false positive errors associated with the Static-99, published in a peer-reviewed journal — Correct?

30. You cannot cite any data, identifying the frequency of false negative errors associated with the Static-99, published in a peer-reviewed journal — Correct?

31. Both Ethical standard 2.05 and Testing standard 7.9 obligate you to acknowledge these many limitations related to Static-99 — Correct?

32. And these many limitations undermining the Static-99 - including its falling short of ethical and practice standards - establish that it cannot claim general acceptance from your professional community — Correct?

Source



Further, questionable -by its author- when used for older offenders:

Abstract:
Static-99 (Hanson & Thornton, 2000) is the most commonly used actuarial risk tool for estimating sexual offender recidivism risk. Recent research has suggested that its methods of accounting for the offenders’ ages may be insufficient to capture declines in recidivism risk associated with advanced age. Using data from 8 samples (combined size of 3,425 sexual offenders), the present study found that older offenders had lower Static-99 scores than younger offenders and that Static-99 was moderately accurate in estimating relative recidivism risk in all age groups. Older offenders, however, displayed lower sexual recidivism rates than would be expected based on their Static-99 risk categories. Consequently, evaluators using Static-99 should consider advanced age in their overall estimate of risk.