Blood Trace Evidence on Washed Textiles - a systematic approach

Luminol has been used for a long time for detecting latent blood traces during police investigations because it is easy to use and does not pose any health risks, while providing trace evidence for DNA analysis. It is often the method of choice for examining clothing. Clothes worn during the offense are often destroyed or washed afterwards by the offenders. The purpose of this study is to show the possibilities of blood and DNA detection on washed clothes by documenting the macroscopic results and their chemiluminescence after washing. The tests comprised different fabrics and laundry detergents including different washing and drying methods. Chemiluminescence was detected on almost all blood-marked samples (95.9%), even after all traces visible to the naked eye have been removed by washing. Evidence of a complete DNA profile or individual alleles could be confirmed in almost all of the test cases (93.3%).