A uniform approach to determine measurement uncertainty in routine chemical forensic casework.

In routine forensic chemical casework where measurements are performed on reference materials, determination of measurement uncertainty is described in several guidelines. The proposed methods often have the drawback that they are not derived from a statistical framework and may lead to conservative confidence intervals. Furthermore, the formulas involved may vary considerably for different types of reference material.

Quantifying Uncertainty in Estimations of the Total Weight of Drugs in Groups of Complex Matrices: Using the Welch-Satterthwaite Equation.

In this paper, a method is described to quantify estimations of the total amount of drugs in groups of seized items, including quantification of the precision. Previous work on this topic was based on the assumptions of normally distributed measurements and grouping of items with a common relative standard deviation. In practice, these assumptions are often violated, for example, for data with point masses at 0, or if certain items in a group have a very high standard deviation.

Quantifying uncertainty in estimations of the total weight of drugs in groups of complex matrices.

In case practice at forensic drug departments, multiple items from one seizure are sometimes sent in with the question: what is the total amount of drugs in the seizure? This may be complicated especially if impregnated material is involved such as clothes or rubber. Measurement uncertainty is typically stable on drug percentages, not weights, and subsampling may take place. It is recognized more and more that determination and reporting of uncertainty on estimators are an essential part of obtaining scientifically sound results in the forensic field.

A case of extreme agitation and death after the use of mephedrone in The Netherlands.

A 36-year old man, having injured himself severely by smashing windows in a rage of fury, was arrested by the police. He died despite resuscitation attempts. The forensic autopsy showed many superficial skin lacerations, bruises and minor brain swelling, but there was no definitive cause of death.