VSC ppt forensic science Shailesh Chaubey .pptx

VSC VIDEO SPECTRAL COMPARATAOR FORENSIC APPLICATIONS BY SHAILESH CHAUBEY STUDENT OF FORENSIC SCIENCE & CRIMINOLOGY FROM BUNDELKHAND UNIVERSITY JHANSI UTTAR PRADESH INDIA . THIS PPT SHOWS ABOUT THE FEATURES, APPLICATIONS , CASE LAWS & NEED OF VSC IN FORENSIC ASPECTS FOR DOCUMENT EXAMINATION & HANDWRITING . THIS PRESENTATION WILL HELP TO GET MORE INFORMATION ABOUT VSC BY VARIOUS SLIDES.

1. VSC VIDEO SPECTRAL COMPARATOR An instrument to see the artefacts beneath the surface

2. contents Introduction Principle Features Light sources and uses Applications Advantages Disadvantages A case on vsc References

3. INTRODUCTION It is designed to satisfy the demands of immigration authorities , government agencies and forensic science labs . the VSC includes advanced characterstics for the examination,comparison and authentication of documents including passports and travel records , official letters and breeder documents , banknotes and cheques , works of art and valuable artifacts through the detection of imperfections. Video spectral comparator comprises of the following :- Laser – induced breakdown spectrometer Computer Monitor VSC is an integrated composite system comprising of cameras , various light sources which include ir, lasers , uv etc. And filters that assist in the comparison of questioned document.

4. PRINCIPLE VSC works on the basic principle of light When light is directed towards an object, any of the one of five things usually occurs depending on the emitted wavelength and the composition of the object :– Reflection Absorption Reflection and absorption Transmission Luminescence The Video Spectral Comparator ( VSC ) uses filter to vary the light bombarding the document . the document is viewed through a camera and computer monitor . As the wavelength of the light is varied , the picture changes.

5. LIGHT SOURCES AND THEIR USES Incandescent filament lamps Narrow-band illumination Coaxial light Spectrum screen Range : 400-1000nm Function of flood, transmitted , spot and side lighting. Trigger fluorescence IR region above 800nm & lacks visible light Perpendicularly on the document Retro- reflective features in security documents This feature hidden under normal light but exposed when the incident light is exactly coaxial to the angle of view. Micro spectrometry with resolution of up to 9nm Shows chromaticity chart and a spectral graph after a spectrum has been recorded In special graphs , one can read the plots of intensity VS the wavelength from 400-1000nm.

6. Features VSC is a general workstation and casework management system for document examiners featuring the following- HI-FI IMAGING TECHNOLOGY An optical system that reduces spatial distortions and chromatic aberration throughout the entire magnification range after excellent image quality. FULL RANGE LIGHT SOURCE It includes incident and transmitted ultraviolet to infrared plus high-intensity illumination for the examination of infrared fluorescence of inks. GRAPHIC USER INTERFACE Innate, on screen control method permits the operator to operate the system more easily.

7. FEATURES High-resolution imaging system Multiple Laser I mages (MLI) : MLI and changeable laser images can be viewed using the VSC ’s sidelights . Alternatively ,the VSC range of hologram imaging LED’S can be used giving great versatility. VSC updated software is integrated with the document database system (with a single user-license) that permits the operator to create their database of security documents . Keesing is a reference database of security documents i.e. passport ,id card, driving license of 180 countries , comprises images and data. Access to optional reference database enables comparisons with authentic security documents.

8. APPLICATIONS OF VSC Reveal latent images and watermark : latent images and watermarks are a commonly used security feature on banknotes worldwide. A latent image is visible only when viewed at an acute angle under reflected light and the watermark is viewed under transmitted light. Anti strokes illuminator Examining uv activated security features vsc is designed for the visual examination of questioned documents and security documents. It is used by immigration authorities and forensic labs. It is effective on all types of passports and identity cards It helps to detects alterations and counterfeits.

9. APPLICATIONS Banks – with VSC each security feature of bank notes can be observed like ink, images, paper gradient and security thread. It can be used to examine suspected fake cheques. Enhancement of handwritings on charred documents. Establishing the chronological order of intersecting printed strokes and writing pen strokes. It provides documentary evidence for prosecutions. Examination of documents under high magnification can quickly reveal evidence of tampering. Government offices – examination of fake official documents fraudsters create fake certificates , notarized documents, license agreements , degree certificates , birth certificates etc. VSC can be very useful to examine such documents and establish authenticity of it.

10. ADVANTAGES OF VSC Convenient and comprehensive for the non-destructive analysis of ink and paper Helps to detect differences between ink in terms of chemical formulation & it reveals writing that has been added using a different ink. Reveals altered or removed writing using variations in the way different inks respond to different wavelengths of light. Visualizes the security features printed into papers & allow quick examination of the questioned document “Foster & freeman” noted that non destructive vsc examination makes it possible to establish the authenticity of an item, detect changes that have been made and to see beneath the surface of an artifact revealing its history.

11. DISadvantages The results obtained by using the vsc are only indicative and not definite because the machine only compares one set of data to another . Furthermore, when using the vsc for examination , comparison can only be done when the specimen comparison is available . Used only for differentiating purpose and not for identification purpose. The instrument is very costly. Not possible to carry the machine at the crime scene.

12. A CASE ON VSC Fluorescence is also used to detect deteriorated , obscure, indecipherable ,or invisible evidence. In one landmark case, the Miami-Dade police department crime laboratory was able to recover a telephone number written on a murder victim’s palm. The number could not be read with the naked eye or with magnification but it fluoresced under the vsc. When investigators went to the address to which the number was traced , the murderer opened the door and confessed.

13. REFERENCES VSC https ://forensicfield.blog/video-spectral-comparator-vsc / VSC http :// epgp.inflibnet.ac.in/epgpdata/uploads/epgp_content/S000016FS/P000695/M011512/ET/1516250916FSC_P8_M33_e-text.pdf https://regulaforensics.com/en/products/advanced_verification/4307 / VSC CASE - https :// www.fraud-magazine.com/article.aspx?id=4294967851

14. THANK YOU END OF THE PPT