ExpertPages Profile | Firm Website | LinkedIn |
In 1984, Ed founded Primeau Productions Inc., a full-service multimedia production company that provides consultation and services for businesses, professional speakers and entertainers, helping them to effectively promote their talents by developing marketing tools and strategies using the power of multimedia formats on the internet.
Ed is the author of “The Art of Production” a book about multimedia production including techniques, pre to post production time and money saving ideas and techniques as well as packaging and marketing multimedia products.
In addition, Ed is also a respected audio visual forensics specialist, analyzing audio and video media components and providing expert witness testimony to assist attorneys, courts and government agencies. Highlights of his forensics forte include audio and video authentication, analysis, and clarification; voice identification, sound and video restoration and clarification.
Video enhancement has become one of the most sought after activities of video forensic experts around the world. During the Boston bombings CCTV cameras outside retail stores helped the FBI capture the criminals.
One of the reasons CCTV video needs enhancement is because too often CCTV cameras are not properly maintained. Worse yet, the cameras are not positioned properly.
In the following article I will provide you with a few particular tips when your CCTV video needs to be enhanced so you can more clearly see criminals as well as events as they occurred.
Always begin with the original video recording. If you have to export an AVI file to provide to police, keep a back up on thumb drive just in case. If all you have is a copy on DVD, then load the DVD directly into your computer for enhancement.
Use a professional software program to enhance like Final Cut Pro, Adobe Premiere Pro. Primeau Forensics uses these as well as Adobe Photo Shop to enhance images exported from the CCTV video. Remember, you can also export frames as still images to identify criminals.
Color correct your footage before performing any other enhancement filtering. This is especially important if your footage is dark and was recorded at night. Be careful not to add too much brightness. Consult a video forensic expert if you have CCTV enhancement questions
If you need to enlarge a portion of the video viewing area, do so after you review the footage on a large video monitor. Remember, the larger the playback monitor, the better you can see events in the video and the less you need to enlarge your video as an enhancement step.
If the CCTV system that made the recording you wish to enhance, before contacting a video forensic expert, learn the type of equipment that made the video you are enhancing. Often times a poor CCTV video export may be to blame for the poor video quality.
Document every step of the clarification process to validate your videos in court.
Video enhancement is an art as well as a science. Try different filtering to get different results. Always begin with the largest file size and structure as close to original digital video as possible. Lastly, before buying video enhancement software, you can download a trial version and determine if you feel comfortable using the software or would rather contact a video enhancement expert.
There are more digital video file varieties in surveillance video than any other form of digital video. The reason for this is because each manufacturer programs their own proprietary digital video format in order to keep their CCTV video recordings secure. When a crime has been committed and caught on video, the video forensic expert must decide the best way to acquire that proprietary video so that it can be used as evidence in court.
Most CCTV systems have export features. Video and images can be removed from the CCTV system easily and securely. This exporting feature is not always the best method from a forensic perspective. Exporting video from the CCTV surveillance system often compresses the digital video file too much for the video forensic expert to enhance. In order to enhance a portion of surveillance video the video forensic expert must start with the highest quality possible.
I have found through experimenting that screen capture programs like Camtasia can create digital video exhibits of much higher quality than many CCTV surveillance systems. Lately, for every case I investigate that requires digital video enhancement or clarification, I use both the CCTV system export (usually an AVI file format) as well as a screen capture from Camtasia to compare the quality.
Most law enforcement authorities use a screen capture method because it is faster at the scene of the crime to capture the video evidence instead of exporting.
I often realize that the compression that the proprietary player exports is not suitable for forensic examination and clarification. The system export resolution and bit rate are too low for a video forensic enhancement starting point.
On the other hand, I can set my screen capture specifications much higher for resolution and bit rate when recording the same series of events on the CCTV system video monitor. Camtasia has an HD option for exporting that dramatically increases the bit rate and data rate providing a much better starting point for enhancement and clarification. Because I have both the export and screen capture videos, there is no doubt about chain of custody and process documentation for my forensic report.
I will be creating a series of videos in the near future using Adobe Premiere Pro for video enhancement and clarification using both methods to further exemplify the necessity for both methods of evidence gathering.
As an audio forensic expert, one of my day-today activities is voice identification. There is a misunderstanding about voice identification that has confused our courts in the United States creating the perception that voice identification testing is not a reliable science. In the following article, I hope to clear up the misconception of voice identification testing as well as communicate some ‘outside the box’ testing techniques that have successfully solved cases where other forms of identification were not possible.
Our court system is full of digital audio recordings that are evidence in criminal proceedings as well as civil litigation. As an audio forensic expert, I have testified in many cases in the United States and worked on cases around the world that involve voice identification. Voice identification is a viable science that involves both science and art. By art I mean discretion of the audio forensic expert to use ‘outside the box’ investigation techniques to help move along due process.
Some of the time my ‘outside the box’ voice identification testing is a matter of life and death. When a company receives a threatening voice mail recording and has an idea of who made that recording, they will call an audio forensic expert like myself and ask for our third party, unbiased opinion. Because I have no stake in the outcome, I can proceed with the untraditional testing in order to deliver my opinion of the probability of the suspect being the one who left the threatening voice mail message.
This serves two purposes. First it helps the organization know that professionals are looking into the origin of the threatening voice mail message. This is comforting to employees especially the employee who received the voice mail message. Secondly, it helps with the conviction process. In other words, when I deliver an opinion, I use a percentage of probability in my initial verbal report. The organization then takes that professional test result to the accused and some of the time they admit or confess and other times they agree or consent to cooperating with the investigative team to create an exact exemplar for more in-depth voice identification testing.
The starting point for any voice identification test is to be able to clearly hear the voice in question that is to be identified. Part of this initial process is to remove any background noise in the audio recording that is unnecessary and distracting to the expert’s sound perception. This noise removal is a process like peeling an onion. The goal for the audio forensic expert is to create custom filtering that increases the volume of the voice in question and remove any unnecessary background noise. This noise reduction filtering process is done a step-by-step, incrementally fashion.. In other words, part of the background noise is removed then the volume of the voice in question is increased. This step-by-step process is the discretion of the voice identification expert. The reason why the expert makes decisions one at a time is because every recording is different.
When conducting a voice identification test, an audio forensic expert looks for spectrums that match the recording in question against the exemplar. An exemplar is a comparison recording that a forensic expert creates of the voice in question for comparison purposes. Even more important are the words themselves. The way the words are pronounced, the pacing of the words pronounced, the space between the words, the articulation of the words and the idiolect of the speaking word delivery style—all are indicia of a voice.
No two human voices are the same ,just like no two fingerprints are the same. Regardless of attempted voice disguise cover up, a trained forensic expert can identify a voice and compare to another to determine identification.
With experience, a trained audio forensic expert can use voice identification skills in a variety of ways and help uncover the truth behind audio recordings.
For example, in the case of the ‘who cried for help’ question around the Trayvon Martin killing in People V. George Zimmerman, there are only screams, not words that an audio forensic expert can compare and identify to the best of their ability. I have formed an opinion about who I believe cried for help before Trayvon Martin was killed by George Zimmerman and have written several blog posts about my opinion. I have also appeared on national television discussing my process and opinions. This is ‘outside the box’ voice identification testing. Is it reliable? In my humble opinion the answer is yes.
Regardless of the type of voice identification testing, the second step, once the recording is as clear as possible, is to create a comparison file that includes back-to-back samples of speech from the accused (exemplar) as well as the evidence or threatening recording. I did this in the case of George Zimmerman before I formed my opinion. Using the example of the threatening voice mail message, each telephone message included two voices. The goal is to determine what percentage of possibility that both voices came from the same person.
During the investigation, I separate the voices – the suspect and the evidence – and create a new audio file called ‘comparison’. That way I can critically listen to all voices back to back in order to determine if any of the voices were identical or at least had similar characteristics.
Once I complete this back-to-back assembly process, I create work notes listing all the similarities as well as differences observed during the critical listening phase of the voice identification testing.
These notes help me provide my opinion and create a report explaining my processes when the voice identification testing is complete.
I also use spectrum analysis and sonograms to help arrive at a conclusion with the identification process. Often I print out the display of these two electronic measurement devices and include these images in my report.
One thing I have learned over the 29+ years as an audio forensic expert: keep it simple. Judges and juries like an uncomplicated decision from a qualified forensic examiner. They become frustrated when they have to interpret new information they have never heard of or are not familiar with.
Voice identification is both an art and a science. As a voice identification expert, I use my talent, skill and ability in every case I am assigned to. The science is acceptable in court and the art is the ability to adapt every case to scientific standards.
Use for marketing or solicitation is prohibited. ExpertPages® and AttorneyPages® are trademarks and units of Advice Company™. For feedback or listing information only, contact us.