N-Benzylpiperazine was tested in the beginning of the 1970s as a possible antidepressant drug. However, in both animal and human studies, it was shown to possess amphetamine-like properties, and any further studies were stopped. In a forensic autopsy case in 1999, we found a substance so far unknown to us in the chromatogram of our method used for amphetamines. We could swiftly identify this compound as N-benzylpiperazine because of information given to us by a newly formed network comprising, among others, customs and the police. Since then, we have found N-benzylpiperazine in several cases, among them 11 cases from a number of prisons.