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Welcome to the Forensic Multimedia Analysis blog (formerly the Forensic Photoshop blog). With the latest developments in the analysis of m...

Thursday, January 31, 2019


One of the scenarios that multimedia analysts find themselves in when doing casework is reproducing the work of others. Sure, you've been trained on the tools that you use. But, have you been trained on the tools that others use? This is one of the many reasons I have always advocated analysts have a "one of each" mentality. Get all the available tools. Get all of the available training.

If opposing counsel's analyst has used Adobe products, for example, do you the training and experience with these tools? What if the analyst is using an older version of the tools?

As an example of this, I have an old laptop with Photoshop CS2 running the legacy scripts from Reindeer Graphics. Sure, Chris Russ has new tools available, like his new Forensic ID plug-in. I like Forensic ID. I like that I can visually adjust the deconvolution filter, not relying so much on specific numbers and targeting the results. But, there are still times when I'll need the old stuff (cold case work, appeals, etc.). That's why I keep everything.

If you're a Adobe Creative Cloud subscriber, you can access older versions of their tools via the web site. The "Other Downloads" page has a complete listing of the legacy versions, each coming with specific warnings about updates and security. I recommend installing these in Virtual Machines so as to not compromise your host OS' security.

Find the needed installer. Install it into a VM (I like VirtualBox). Take the opposing analyst's notes. Attempt to reproduce the work and results. Document your work. Done.

Over at the Amped Support Portal, similar functionality exists for users with current support contracts. You'll find the change log and installers for previous versions.

For other tools, like Doug Carner's Video Cleaner, only the current version is readily available on the company's web site. If you're using a tool from a company that only hosts the current release, you'll want to keep a copy of each version's installer. If you're working the other side of a case, and the analyst is using an older version of VideoCleaner, or similar tool, you'll likely have to reach out to the developer / company for the older version's installer. Whilst Doug is a nice man and will likely send you a download link rather quickly, other companies might not be so accommodating. It may take a request from the court, written to the software company, to get the older installer and a temporary license. Or, as has happened to me, the court may rule that you're not allowed to use your preferred tool as it's not available to the other side (licensing restrictions, cost, etc.).

This year, reproducing others' work in various tools will be the focus of a series of informational videos that I'll be creating and hosting over at Screencast.com. Stay tuned for that.


Monday, January 28, 2019

Training Notice: Statistics for Forensic Analysts

I'm pleased to announce that Apex Learning, our state-of-the-art learning portal, is officially launching today with our first offering - Statistics for Forensic Analysts.

Statistics play an important and expanding role in criminal investigations, prosecutions and trials, not least in relation to forensic scientific evidence produced by expert witnesses. The Royal Statistical Society (UK) began a process in 2010 to inform and educate stakeholders in the justice system in with their publication of Fundamentals of Probability and Statistical Evidence in Criminal Proceedings. From that original work product, a total of four publications have been produced from the Society’s Statistics and the Law Section. Simultaneously, the National Commission on Forensic Science (US) began to study the issue. Several of its subcommittees have informed the discussion on the use of statistics in forensic science, issuing various guidance documents to the US Department of Justice. In 2015, the US state of Texas passed SB-1287 creating a licensing program for forensic science practitioners and analysts. Within the Texas licensing program, analysts will be tested across a variety of foundational domains in order to obtain licensure, including statistics.

What's different about Apex Learning?

To accommodate learners around the world, we're packaging these courses as micro-learning and delivering them on-line. Upon sign-up, learners have up to 60 days to complete each course.

We're leveraging a state-of-the-art learning management system to deliver quality training and education offerings that can be accessed from anywhere in the world. This reduces the cost to train / educate each analyst dramatically. We're passing the savings on to the customer, as you'll see in our first offering's price.

With PayPal, we can accept payment in the majority of the world's currencies. For institutional orders (multiple students from the same agency), we can accept bank transfers in over 30 currencies from our European based TransferWise accounts.

Our courses aren't designed to compete with anyone's offerings. They're designed to complement them by adding depth and breadth, shoring up topics that the average analyst might not be exposed to.

Stay tuned as we roll out more offerings. It's going to be a great year.

Tuesday, January 22, 2019

Training Notice: Redaction for California SB1421 / AB748 Compliance

Training Notice

Recent legal changes in California have impacted the way in which agencies handle video / multimedia evidence requests from the public. Complying with the new laws, and maintaining compliance with state and federal privacy codes requires agencies to manage the processing of requests quite carefully. Requests for records around a critical event can quickly swamp an agency’s staff given the new statutory time frames for the release of data.

Senate Bill 1421, Skinner (D. Berkeley), opens public access to internal investigations of police shootings and other incidents where an officer killed or seriously injured someone, as well to sustained findings of sexual assault and lying on the job.

Assembly Bill 748, Ting (D. San Francisco), requires police departments to release within 45 days audio or video footage of shootings or other incidents involving serious use of force, unless it would interfere with an active investigation.

This in-person course will get the agency and their redaction staff up to speed on the issues and the technology necessary to bring the agency into compliance with the new laws.

Location: Apex Partners, Ltd., Henderson, NV USA

Date: April 2-3, 2019

Product Information: Adobe Creative Suite

Click here for more information and to sign-up for this course.

This course can be brought to the agency. Visit the web site to find out how.

Monday, January 14, 2019

Test your report's readability

One of the concepts that I tend to repeat when training folks in the forensic sciences is that our work should target the last mechanical device that will display or project our work products as well as targeting the combined perceptual abilities of the Trier of Fact. Working in this way, there will be no surprises when it comes to presenting your work.

The same is true for your reports. Your reports will make sense to you. You wrote them. They'll make sense to your quality control staff (your reviewers) as they tend to exist in the same culture and climate as you. But, will they make sense to the Trier of Fact - without you having to explain it to them?

There is functionality within our toolset to help with this question - how readable is my report? If you're using MS Word to draft your reports, it's actually quite easy to set this up.

  • Click the File tab, and then click Options.
  • Click Proofing.
  • Under When correcting spelling and grammar in Word, make sure the Check grammar with spelling check box is selected.
  • Select Show readability statistics.

After you enable this feature, open a file that you want to check, and check the spelling by pressing F7 or going to Review > Spelling & Grammar. When Word finishes checking the spelling and grammar, it displays information about the reading level of the document.

Each readability test bases its rating on the average number of syllables per word and words per sentence. The following sections explain how each test scores your file's readability.

Flesch Reading Ease test (references)

Originally developed for the US Navy in 1975, this test rates text on a 100-point scale. The higher the score, the easier it is to understand the document. For most forensic science processing / analysis reports, you want the score to be between 55 and 70. Given that we'll have to use standard scientific terminology, it will be difficult to achieve readability scores higher than 70.

The formula for the Flesch Reading Ease score is:

206.835 – (1.015 x ASL) – (84.6 x ASW)


ASL = average sentence length (the number of words divided by the number of sentences)

ASW = average number of syllables per word (the number of syllables divided by the number of words)

Flesch-Kincaid Grade Level test

This test rates text on a U.S. school grade level. For example, a score of 8.0 means that an eighth grader can understand the document. For your reports, aim for a score of approximately 7.0 to 10.0. It will prove difficult to bring these values down, as noted above, due to our use of scientific language which gets averaged into the total score.

The formula for the Flesch-Kincaid Grade Level score is:

(.39 x ASL) + (11.8 x ASW) – 15.59


ASL = average sentence length (the number of words divided by the number of sentences)

ASW = average number of syllables per word (the number of syllables divided by the number of words)

The Readability Statistics shown above is from a raw authentication report - before editing and before the insertion of the plain English explanations for each of the processes.

Given that about 95% of cases plea and never see the inside of a court room, it's vitally important that your reports be readable.  95% of your reports will be read, interpreted, and acted upon without your being present to help the reader understand what you said / meant. With this simple tool that is built into many word processing applications, you can assure that your reports are readable, and at what grade level.

If you're using Google Docs, you'll need to run your report through another app or web site. Readability Statistics were removed some time ago.