The use of messenger RNA profiling to identify the origin of biological samples (e.g. blood, semen and saliva) from crime scenes is now at the stage of being implemented into routine forensic casework. The authors report on the successful modification of the Promega DNA IQ system to enable co-extraction of DNA and RNA from the same sample without compromising the potential DNA profile. Using the protocol in the authors' laboratory for extracting DNA using the DNA IQ system combined with the Zymo Research Mini RNA Isolation Kit II the authors demonstrate the simultaneous co-extraction of DNA and RNA from the same sample for routine DNA and mRNA profiling for the identification of both the individual and the biological stain. (Published Abstract) 2 tables, 4 figures, and 11 references