DNA evidence in a serial killer case was analyzed using the AmpliType HLA-DQ alpha-, AmpliType PM-, and the GenePrint STR Multiplex System PCR Amplification Kits. In addition, a sex typing procedure using the X-Y homologous gene amelogenin was carried out. DNA profiles from a single hair with attached sheath material, recovered from underneath the seat cover of the suspect's car seat, were compared with DNA profiles derived from reference head hairs from a homicide victim. From the evidentiary sample only 9 ng of human DNA could be recovered. In a sample, where the quantity of DNA becomes a critical issue, a powerful route is the simultaneous amplification of several loci (multiplex PCR). This is the first report where commercially available multiplex PCR amplification and typing kits have been introduced for the analysis of DNA, evidence in a serial killer case and the analysis has been admitted in court. Figures, tables, references