Human forensic toxicology focuses on the determination of pharmacological effects of alcohol, abused drugs, medications, or other possibly toxic compounds. In most cases, police or prosecutors give the order for a scientific investigation in a forensic case. The analytical results from the laboratory and its scientific expertise will in most cases be used in court. Consequently, all technical, analytical, and expert work needs to be fulfilled with the utmost professional care. A very important part is the chain of custody of evidence, where at any moment in time the origin of every sample and any analytical result must be unequivocally clear. Fields of action comprise the analytical investigation and evaluation of biological samples or suspect items from living or dead persons. Drug abuse and influence of substances that act on the human central nervous system during or just before a certain event (such as traffic accidents, homicide, and submission of sedating drugs) are the most common issues, belonging to the field of behavioral forensic toxicology. To fulfill these tasks, the two biological fluids, urine and blood, are the most frequently used specimens. Recent scientific research also involves new specimens such as sweat and saliva (oral fluid). When investigating on a presumably unnatural death, additional samples from the autopsy (e.g., gastric content and organ tissues) are used. In this field of postmortem toxicology, the scientific goal usually is to confirm or exclude intoxication as the most plausible cause of death. This task is often complicated by various biological, chemical, and physical effects that can occur postmortem (1-7).