Forensic video
Encyclopedia
Forensic video analysis is the scientific examination, comparison and/or evaluation of video in legal matters.
Listed below are common techniques that are required of forensic video analysts.
A tape based VCR that will play back older formats such as S-VHS, 8 mm and Hi8 decks are also recommended, but these older systems can be rented if the need arises.
Another piece of equipment that is no longer needed is an external Time Base Corrector (TBC). At one time this was crucial to doing forensic video work, but newer digital security camera systems make this absolete.
A video monitor capable of displaying the underscan and overscan
area of a video signal.
A forensic video analysis system capable of digitizing analog video in an uncompressed, format.
A professional quality printer from creating court evidence to be used in jury trials is nice, but also not necessary. Best practice is to buy a basic printer for draft printing of images, and then go to a professional photo lab to have high quality enlargements made ready for use in court.
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Understanding Proprietary DVR
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Listed below are common techniques that are required of forensic video analysts.
- Reliably digitize video tape footage onto a computer system. (This is commonly done via Non-Linear Editor (NLE)NLENLE is an acronym. It may stand for:* Non-linear editing system* National Latin Examination* North Luzon Expressway* N.L.E. Tractors, a codename for Cultivator No. 6...
software.) - Be able to demultiplex or separate camera views from multiplexed CCTVClosed-circuit televisionClosed-circuit television is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors....
footage. - Convert digital video from DVR (Digital Video Recorder) devices into digital video formats usable for forensic analysis.
- Perform clarification techniques such as frame averaging.
- Highlight someone or something of interest in the video.
- Enlarge portions of the video for areas of interest.
Standard Operating Procedures (SOPs)
A written, documented set of Standard Operating Procedures (SOPs) should be established to outline the procedures that the analysts are expected to follow during the course of reviewing forensic video evidence. Listed below are items to consider when writing SOP's.- This must be done so that it adheres to the standards of evidenceFederal Rules of EvidenceThe is a code of evidence law governing the admission of facts by which parties in the United States federal court system may prove their cases, both civil and criminal. The Rules were enacted in 1975, with subsequent amendments....
and so it is admissible in a court of law. - They must follow the proper Chain of CustodyChain of custodyChain of custody refers to the chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of evidence, physical or electronic...
with that evidence. - Special precautions must be taken to ensure that the evidence is properly protected and stored. In the case of analog video tapes, the record tab should be removed and for digital video it should be write protected.
- Considerations for peer reviewPeer reviewPeer review is a process of self-regulation by a profession or a process of evaluation involving qualified individuals within the relevant field. Peer review methods are employed to maintain standards, improve performance and provide credibility...
of casework should be made. - Ongoing training should be included and planned. Through professional organizations such as American Academy of Forensic Science, IAI, NATIA, LEVA, local community college courses and also vendor specific training.
Equipment
Although at one time S-VHS VCRs were considered state-of-the-art, today these tape based recording devices are mostly retired from use. Much more important for doing forensic video analysis is a computer editing system and specialized forensic software. Many of these software programs are quite advanced, and the knowledge to operate them is crucial.A tape based VCR that will play back older formats such as S-VHS, 8 mm and Hi8 decks are also recommended, but these older systems can be rented if the need arises.
Another piece of equipment that is no longer needed is an external Time Base Corrector (TBC). At one time this was crucial to doing forensic video work, but newer digital security camera systems make this absolete.
A video monitor capable of displaying the underscan and overscan
Overscan
Overscan is extra image area around the four edges of a video image that may not be seen reliably by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube .-Origins of overscan:Early televisions...
area of a video signal.
A forensic video analysis system capable of digitizing analog video in an uncompressed, format.
A professional quality printer from creating court evidence to be used in jury trials is nice, but also not necessary. Best practice is to buy a basic printer for draft printing of images, and then go to a professional photo lab to have high quality enlargements made ready for use in court.
Organizations
- American Academy of Forensic Science (AAFS)
- Digital Summit International (DSI)
- International Association for Identification (IAI)
- International Association for Pattern Recognition, Technical Committee on Computational Forensics (IAPR-TC6)
- International Society for Optical & Photonics, Investigative Image Processing Technical Group (SPIE)
- Law Enforcement and Emergency Video Services Association (LEVA)
- National Technical Investigators’ Association (NATIA)
- Scientific Working Group on Imaging Technologies (SWIGIT)Scientific Working Group - Imaging TechnologyThe Scientific Working Group on Imaging Technology was convened by the Federal Bureau of Investigation in 1997 to provide guidance to law enforcement agencies and others in the criminal justice system regarding the best practices for photography, videography, and video and image...
Forensic Video Software
- Cognitech
- Ocean Systems dTective
- Salient Stills VideoFOCUS
- StarWitness
- Avid Technology, Inc.
- Intergraph Video Analyst
- TREC, Inc.
- Forevid
- MotionDSP Ikena
- Amped FIVE
- Kinesense
- Paraben (Video Recovery from Mobile Device and Hard Drive)
- Cellforensics (Video Recovery from Mobile Device)
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Knowledge Bases
- 11 Tips for gathering and utilyzing security camera video evidence
- Comprehensive Glossary on Video Formats
- How to Forum on Video Projects
- Ocean Systems Knowledge Base
- Media-Geek.com - A community resource site for Forensic Media Analysts.
Understanding Proprietary DVR
Proprietary DVR
DVRs, or Digital Video Recorders, are devices which record video to a hard drive. The term Proprietary DVR refers to exclusive methodologies used to maintain commercial control over the DVR format and prevent third-party copying of a particular file...
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