Lethal injection of potassium chloride: first description of the pathological appearance of organs

Lethal injection of potassium chloride (KCl) can be used as a method of either suicide or homicide. As biological tests are still inadequate to differentiate endogenous from exogenous potassium, at the scene of death the cause can only be suspected. We wished to determine the usefulness of conventional pathological examination in this context and carried out a study in four fetuses after medical termination of pregnancy for serious disease. Pregnancy was terminated by KCl injection in two cases and by injection of lidocaine and sufentanil in the other two cases. In each of the two fetuses in which KCl injection was performed, macroscopic examination showed whitish deposits on the tissues and histological examination showed clumps of lanceolate crystals in the internal organs. In the two fetuses which received lidocaine and sufentanil injection, no deposits were visible on macroscopic examination and no crystals were seen on histological examination. These findings suggest that pathological study may have useful applications in forensic medicine when death by potassium injection is suspected.