A high-performance liquid chromatography (HPLC) laboratory experiment based on the separation of four prescription drugs (disopyramide, lidocaine, procainamide, and quinidine) is presented. The experiment is set within the forensic science context of the discovery of a patient's mysterious death where a drug overdose is suspected. Each lab group is provided with drug standards of known concentration and a simulated "blood" extract from the patient. Each group must determine whether the patient died of a drug overdose or through natural causes. This requires each drug standard to be analyzed separately to determine its retention time. The group must then analyze the "blood" to identify which drugs are present. After establishing the identity of any drugs present in the "blood", multiple drug injections of varying concentrations are performed to construct a calibration curve of peak area versus concentration. This can be used to determine the quantity of each drug present in the "blood". The students must also search the literature to determine possible drug interactions as well as normal and lethal doses of each drug, before reaching a conclusion about whether the patient died of a drug overdose, and if so whether it was likely accidental or intentional. (Contains 2 figures and 1 table.)