crimescopes and related devices
I did a little bit of research into crimescopes and related devices and how they detected semen. Semen fluoresces when excited with light between 300-480 nm in wavelength, according to the second link below.
http://projects.nfstc.org/workshops... the Detection of Semen Stains on Fabrics.pdf
The paper above (Kobus, HJ, et al., J Forensic Sci, July 2002, Vol. 47, No. 4) states, “Over the past few years the “Polilight” has been used routinely in the authors’ laboratory for the detection of dried semen stains in sexual assault cases. The technique is used as a screening method to target suitable areas for acid phosphatase testing and subsequent DNA analysis.” It also lists another paper as a reference, possibly the first one for detection of semen by fluorescence: 1. Stoilovic M. Detection of semen and bloodstains using the Polilight as a light source. Forensic Sci Int 1991;51:289–96.
The senior author of this paper is also known in DNA forensic circles:
http://projects.nfstc.org/workshops...of Polilights in the Detection of Seminal.pdf
Below is some information from two manufacturers. The Carabinieri bought 107 of the crimescopes recently.
http://www.crimescope.com/
Typical applications of our Forensic Lights:
Fluorescence (Ultraviolet, all Visible wavelengths, Infrared),
Reflectance, Absorption used for: Latent fingerprint identification, Crime Scene Search and evidence collection, Forensic photography and imaging, forged/questioned documents, counterfeit, biology & serology (detection of semen, blood(in natural absorption mode at 415nm or in fluorescence mode after treatment with the Fluorescein spray), saliva, vaginal fluids, sweat, feces…), footprint, gun shot residues, bruises, bite marks, fibers and hair, bone fragments.
FLS Selection:
Our Forensic light sources, CrimeScope, Mini-CrimeScope and HandScope are manufactured in Edison, NJ, USA by JY Inc. SPEX Forensics Division. They are the ultimate units in their categories featuring the most wavelengths and highest intensity (best sensitivity in searching mode). Over the past 6 years
SPEX Forensics has become the worldwide leader in FLS with the purchase of
50 units by the National Japanese police, 140 units by the FBI, 25 units by the French Gendarmerie, and more recently 107 units by the Italian Carabinieri. There are more than 1000 units in use worldwide by police forces ranging from small City Police Dept’s to counties, state and special crime scene forces to national and federal police agencies. (Note the FBI can not endorse any particular brand)
http://www.horiba.com/scientific/pr...t-sources/forensic-light-source-applications/
Body Fluids
Since body fluids like semen, saliva, and vaginal fluids are naturally fluorescent, the use of a light source offers a unique method for locating them. A crime scene investigator can narrow down the specific locations of stains for collection instead of testing entire, large pieces of evidence such as a mattress, a carpet, a sheet, an article of clothing, etc.. The dried body fluids will actually glow under the light source illumination. Although the body fluids will fluoresce under an ordinary UV black light, many articles on which you would find them including clothing and sheets will also glow and deter their detection. It is therefore necessary to tune to visible color bands (wavelengths) to eliminate the background interference. Considering you will be searching for body fluids on high profile, capital crime cases, the more body fluid evidence you can reveal the better. Again, the more powerful and more tunable your light source, the more evidence you will uncover.