Benzodiazepines were analyzed in different tissue samples, including bone, by ELISA. The sensitivity of detection for different benzodiazepines was consistent with the manufacturer's reports of the cross reactivities of the antibodies used, with the greatest sensitivity for midazolam and the least for diazepam; in addition the pharmacokinetics was consistent with the known duration of action of the different benzodiazepines, with midazolam cleared rapidly, and diazepam slowly. Following intramuscular injection of 300 μg of midazolam at 16 h intervals for ten days, the drug was detectable in bone tissue samples obtained from skeletonized remains buried in soil at room temperature for three weeks.