Cannabinoids in blood and urine after passive inhalation of Cannabis smoke

To test the possibility that cannabinoids are detectable following passive inhalation of Cannabis smoke the following study was performed. Five healthy volunteers who had previously never used Cannabis, passively inhaled Cannabis smoke for 30 min. Cannabis smoke was provided by other subjects smoking either marijuana or hashish cigarettes in a small closed car, containing approximately 1650 L of air. delta 9-Tetrahydrocannabinol (THC) could be detected in the blood of all passive smokers immediately after exposure in concentrations ranging from 1.3 to 6.3 ng/mL. At the same time total blood cannabinoid levels (assayed by radioimmunoassay [RIA] ) were higher than 13 ng/mL in four of the volunteers. Both THC and cannabinoid blood concentrations fell close to the cutoff limits of the respective assays during the following 2 h. Passive inhalation also resulted in the detection of cannabinoids in the urine by RIA and enzyme multiple immunoassay technique (EMIT) assays (above 13 and 20 ng/mL, respectively). It is concluded that the demonstration of cannabinoids in blood or urine is no unequivocal proof of active Cannabis smoking.     

Intentional or accidental suicide? "02 47 41 4D 45 20 4F 56 45 52 21 0D..."

The purpose of the present contribution is to point out an unusual case of composing farewell letters in hexadecimals--a method of writing farewell letters that seems to become more frequent in the rising computer generation. This phenomenon is demonstrated in a case of chloroform suicide.     

Physiological variations in blood ethanol measurements during the post-absorptive state

Specimens of arterial plasma and venous whole blood were obtained at 3-10 min intervals during the post-peak phase of ethanol metabolism in healthy volunteers. The concentrations of ethanol in blood and plasma were determined by headspace gas chromatography. This method had a standard deviation of 0.28 mg/dl for whole blood and 0.26 mg/dl for plasma and the coefficients of variation were 0.43% and 0.79% respectively. The physiological variation from time-to-time, expressed as the residual standard deviation after fitting the ethanol concentration-time regression relationships, ranged from 0.43-3.7 mg/dl (0.65-16%). The time-to-time variations in concentrations of ethanol were maximum when there were problems in getting an unimpeded flow of blood through the indwelling catheters. The results do not support the existence of sporadic fluctuations or spiking in the blood alcohol concentration-time profile during the post-absorptive state. Instead, this study underscores the need to control carefully the method of sampling blood and in this way keep pre-analytical sources of variation to a minimum.     

The Empirical Limits of Forensic Mental Health Assessment

This article introduces a special issue of Law and Human Behavior, including five articles describing the limits of forensic mental health assessments of (a) risk of violence in female adolescents, (b) sexually violent predators, (c) dangerousness in capital murder cases, (d) child sexual abuse, and (e) PTSD litigants. Knowing the limits of forensic mental health assessment methods is essential in order to recognize their strengths, increase the credibility of forensic mental health assessment, and drive research that will enhance the value of assessments for the courts.     

Do Jurors “Know” What Isn’t So About Child Witnesses?

Are expert witnesses needed in child sexual abuse cases to educate jurors about children’s memory, suggestibility, and reactions to abuse, or do jurors already know what such experts could tell them? To cast light on this question, we surveyed jurors and jury-eligible college students and compared their beliefs with what is known via scientific research regarding children’s memory and ability to testify, reactions to interrogation, and reactions to sexual abuse. We also asked participants to infer results of four widely cited studies of children’s suggestibility. Participants’ beliefs were consistent with findings from research on some issues (e.g., that children can be led to claim that false events occurred) but diverged from the scientific consensus on other issues (e.g., whether children can remember painful events in infancy). Similarly, participants sometimes overestimated and sometimes underestimated the level of suggestibility observed in empirical studies. Individual differences in accuracy were related to participants’ gender, education and ethnicity, and there was considerable disagreement among participants on many questions. Implications of findings for the admissibility of expert testimony in child abuse cases are discussed.