Concentrations of morphine and its metabolites were similar in blood taken from subclavian, heart, and femoral regions. A trend existed for higher concentrations in heart blood than in femoral or subclavian blood, but the difference was not significant. No significant difference existed in concentrations between admission and autopsy blood in which the postmortem interval averaged 59 hours. Significant postmortem redistribution of morphine and its metabolites in body tissues appears unlikely. Findings also supported the use of femoral blood, although blood from other sites will have only small increases in the concentration of morphine and its glucuronide metabolites. Tables and 10 references (Author abstract modified)