Our purpose was to identify individuals from blood stains in two murder cases. We used primers flanking the hypervariable region of the apoB gene to amplify DNA extracted from blood stains and blood samples from suspected persons. The sensitivity and specificity of the procedure was improved by carrying out two consecutive PCR amplifications with a nested set of primers in the second amplification. The size of the generated fragments was determined by polyacrylamide gel electrophoresis followed by staining with ethidium bromide. By comparing the fragments produced from the stains with those from the blood samples we were able to identify the origin of the blood stains in both cases.