I don't think the nanotechnology could be used in forensic science dirctly, but the products of naotechnology will be used in the future, such as "DNA microarrays".
Nanoparticles have got some serious business in Forensic Science. An upcoming branch is FORENSIC NANOTECHNOLOGY. Nanoparticles are being used recently in fingermark visualization & development.
Ashish i also like to say there are many work in detection science of explosives and poisons.........but still there is no any single research is used by any forensic lab in world as per my knowledge..........even in Molecular biology...DNA related work are also not taken in to consideration in criminal justice system any where.............
A separate R&D unit should be set up to try Forensic Nano Technology.Already DNA chip has been introduced.We may have surprises in store in other forensic fields.