The fingerprint processing and the DNA processing can be done simultaneously. In fact, the fingerprint collection is beneficial for the processing of DNA evidence, but there is one way that the fingerprint processing can actually impact the collection of DNA evidence, and that is through contamination of DNA due to the fingerprint reagents. According to different researches different samples of blood, fingerprints have been analyzed, and all the possible fingerprint reagents are ranging from Cyanoacrylate to fingerprinting powders to Ninhydrin to reach the profile evidence of DNA of the blood were tested to check how the fingerprint reagents can interfere with the DNA . The sample that interfered with the DNA effectiveness was when the reagents Sticky side powder and the Un-Du were combined together, and the DNA was destroyed, and they were no mark outs of DNA at all . This means, if these fingerprint reagents are present together, then there will be a lot of interference in the DNA collection method. Another possible reagent is fingerprinting powder that can effectively ruin the DNA present at the crime scene.
The hazard for the Touch DNA contamination is that whenever the investigator or anyone else, touches the evidence, the Touch DNA is deposited on the surface of the evidence. It is also possible that the DNA evidence is only placed on four to five skin cells and the evidence can be damaged due to the interference . The self-contamination can occur, if the agent does not wear a glove while he is handling the evidence or if he touches the object at the crime scene that might contaminate the DNA and eventually remove the importance evidence. This can also involve any sort of stain and fingerprint dusting powder that is used at the crime scene for investigative purposes. Hence it is imperative, that small amount of powder is used, and the remaining is discarded in order to prevent contamination.
References
Guardian Forensic Sciences. (2016, Feb). Retrieved Jan 21, 2017, from Effect of Fingerprint Processing on DNA Analysis: http://www.guardianforensicsciences.com/effect-of-fingerprint-processing-on-dna-analysis.html
Molina, D. (2007). Use of Un-Du to Separate Adhesive Materials. Journal of Forensic Identification , 688 to 696.
Sowmayya. (2016). Touch DNA: An Investigative Tool in Forensic Science. International Journal of Current Research , Vol.8, Issue 02, pp. 26093-26097.
