A review of the techniques used by Nizhny Novgorod forensic physicians in studying the possibility of using biochemical methods in expert practice is presented. Changes at the molecular level in pathological conditions precede functional and morphological disorders in tissues and organs. The use of biochemical methods — in particular, the study of the concentration of myoglobin and substances of low and medium molecular weight — significantly expands the possibilities of forensic-medical ekspertise. The authors study investigated the effect of the sampling period and the storage conditions of biomaterial on the results of biochemical studies; the dynamics of myoglobin content in determining whether a victim was dead or alive at the time of injury, and how long ago the injury occurred; and the nature of ischemic myocardial damage. The possibility of using substances of low and medium molecular weight in determining the cause of death was evaluated.