A Classification Tree Approach to the Development of Actuarial Violence Risk Assessment Tools

Since the 1970s, a wide body of research has suggested that the accuracy of clinical risk assessments of violence might be increased if clinicians used actuarial tools. Despite considerable progress in recent years in the development of such tools for violence risk assessment, they remain primarily research instruments, largely ignored in daily clinical practice. We argue that because most existing actuarial tools are based on a main effects regression approach, they do not adequately reflect the contingent nature of the clinical assessment processes. To enhance the use of actuarial violence risk assessment tools, we propose a classification tree rather than a main effects regression approach. In addition, we suggest that by employing two decision thresholds for identifying high- and low-risk cases--instead of the standard single threshold--the use of actuarial tools to make dichotomous risk classification decisions may be further enhanced. These claims are supported with empirical data from the MacArthur Violence Risk Assessment Study.     

Segmental analysis for cocaine and metabolites by HPLC in hair of suspected drug overdose cases

Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29-316 ng/mg of hair for cocaine, 0.43-141 ng/mg of hair for benzoylecgonine and 0.93-1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.     

Detection of THCCOOH in hair by MSD-NCI after HPLC clean-up

Regular consumption of cannabis can easily be detected by examination of hair for tetrahydrocannabinol, cannabinol, and cannabidiol. Although several studies have demonstrated that after contamination with smoke or treatment with THC containing shampoos THC is not detectable, or only in small traces, the detection of 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (THCCOOH) should be offered to prove the consumption and metabolisation of THC. Up to now this confirmation was only available using tandem MS techniques combined with negative chemical ionisation. A new method using a normal quadrupole GC/MS is described. The lack of expensive instruments has to be paid for by a costly and time consuming extraction and clean-up. After the sample has been digested by 2 M NaOH at 95 degrees C and the neutralised liquid has been extracted with a mixture of n-hexane and ethyl acetate the dried residue is reconstituted in acetonitrile-methanol-0.01 M sulfuric acid (49:21:30, v/v/v) and the cannabinoids separated by HPLC. Each fraction is collected over 1 min. Another extraction with n-hexane-ethyl acetate is followed by evaporation, derivatisation, and GC/MS determination. The calibration with THCCOOH spiked hair led to a LOD of 0.3 pg/mg and a LOQ of 1.1 pg/mg.     

Computer-assisted facial image identification system using a 3-D physiognomic range finder

This system consists of a 3-D physiognomic range finder and a computer-assisted facial image superimposition unit. The 3-D range finder is composed of a detector for measuring facial surface and its control computer. The detector has two sinusoidal grating projection devices and two CCD cameras. The computer-assisted facial image superimposition unit consists of a host computer including a proprietary software, a flat surface color display and a color image scanner for inputting 2-D facial images of a criminal. The 3-D facial shape and texture of a suspect is obtained by using the range finder. To make the comparison between the 3-D facial image and the 2-D facial image, the 3-D facial image is first reproduced on a display of the host computer from a MO disk and then the 2-D facial image is taken with the color image scanner and reproduced on the display. The 3-D facial image is exactly adjusted to match the orientation and size of the 2-D facial image under the fine framework mode, and then the fine framework mode of 3-D facial image is converted to the fine texture image. The shape and positional relationships of facial components between the 3-D and 2-D facial images are examined by the fade-out or wipe image mode. The distance between the selected two points and angle among the selected three points on the 3-D and 2-D facial images are automatically measured for the assessment of anthropometrical data between both images. For evaluating the fit between the anthropometrical points on the 3-D and 2-D facial images, the reciprocal point-to-point difference between both images is compared.     

An analysis of the usefulness of specific stages in the pathologic investigation of sudden infant death

Retrospective analysis of autopsy findings in 60 infants who had been found unexpectedly dead in their cribs or beds in South Australia from 1994 to 1998 was undertaken to determine the diagnostic usefulness of individual stages in the postmortem investigation. Positive findings occurred in 2 of 43 scene examinations (3%), 2 of 60 external examinations (3%), 2 of 11 radiologic examinations (18%), 8 of 60 internal examinations (13%), 7 of 60 histologic examinations (12%), and 3 of 58 microbiologic examinations (5%). No positive findings were detected on toxicologic screening. Not every case underwent each diagnostic step. This gave alternative diagnoses to sudden infant death syndrome (SIDS) in 15 cases (25%). This study demonstrates an increase in the percentage of cases of unexpected infant death due to causes other than SIDS; it also shows the diagnostic yield of individual stages in the postmortem evaluation of such cases. Negative findings were important in giving validity to the diagnosis in the 45 cases that were ultimately designated as SIDS.     

Wrapped in silence: psychotherapists and confidentiality in the courtroom

The impact of the Austrian Psychotherapy Act, which, in contrast to legal provisions in the United States, does not provide for any exceptions to breach confidentiality, is compared with the effects of U.S. law on dealing with confidentiality. The authors investigated the impact of this law in light of three common situations in psychotherapy that may jeopardize strict confidentiality: treating potentially dangerous patients, giving testimony, and serving as a psychotherapist in prison. Under the strict provisions of the Austrian Psychotherapy Act, a breach may be excusable in the case of a highly probable danger, but Austrian psychotherapists cannot be obliged to serve as witnesses or as experts in civil or criminal cases, as American psychotherapists can. Psychotherapy in prison, where release is contingent on the success of the therapy and the divulging of information could be in the interests of the patient as well as the court and the public, requires a modified dealing with confidentiality.