Journal of Forensic Research

In a past study, we developed multiple linear regression (MLR) models that employed three single nucleotide polymorphisms (SNPs) that predicted a significant proportion of variation in pigmentation phenotypes from a large population cohort (n=789, training sample). Multiple linear regression models were developed for skin reflectance, eye color, and two aspects of hair color (log of the ratio of eumelanin-to-pheomelanin and total melanin). In this report, using an independent cohort (n=242 , test sample), we 1) externally cross-validated the prediction models, and 2) tested and refined the algorithm presented in the study by Valenzuela and colleagues, (2010). Relative shrinkage was moderate for skin reflectance (23.4%), eye color (19.4%), and the log of the ratio of eumelanin-to-pheomelanin in hair (37.3%), and largest for total melanin (67%) in hair. Independent construction of predictive models using our algorithm for the test sample set yielded the same or similar models as the training sample set. Two of the three SNPs composing the models were the same, with some variability in the third SNP of the model.

Based on toxicology findings performed on samples taken at the time of autopsy, the cause of Michael Jackson’s death was determined to be acute propofol intoxication with a contributory benzodiazepine effect. The manner of death was determined by the coroner to be homicide. At the center of this case are several anesthetic medications. Insight into the toxicology, review the autopsy results, and summary of the findings are provided from a forensic anesthesiologist’s point of view.