Auto-Categoriser (AC): A Global Breakthrough in Automating CSAM Categorisation

Semantics 21 (S21) are pleased to announce the public launch of S21 Auto-Categoriser (AC), the newest and most advanced AI engine for categorising child sexual abuse (CSAM) material. S21 Auto-Categoriser is now available as a complimentary upgrade to both new and existing S21 LASERi-X users. It has been developed with the assistance of law enforcement across the ‘Five Eyes’ nations.

The wait is over! The capability to automatically identify hundreds of thousands of CSAM images and videos in minutes is now a reality.

Designed to work alongside investigators as a powerful intelligent filter, to enhance investigations, S21 AC has been proven to:

  • Significantly reduce categorisation time
  • Determine the severity of media autonomously,
  • Enable investigators to review notable media faster and potentially highlight victims quicker, 
  • and enhance user wellbeing.

  • Complimentary upgrade for all, available immediately for existing S21 LASERi-X users (available to new customers with the release of LASERi-X v2.1, in December).
  • Works with all third-party software through LASERi-X’s ability to streamline the import and organisation of multiple sources of evidence into a single analysis. Computers, tablets, phones, cloud, etc, all ingested into a single tool and automatically categorised and reported upon.
  • Built using state-of-the-art AI designed from the ground-up to classify media as CSAM, CSAM indicative, adult pornography, or non-notable. Developed in-house and continually improved to keep up-to-date with the ever changing trends.
  • Benchmark-leading accuracy and performance, with users reporting “fantastic” prediction accuracy and processing speeds of 900,000 files categorised in 80 minutes using their existing hardware, and a reduction in overall case processing time by 40-60% (figures based on actual user feedback). Users can even continue to use LASERi-X as normal while the AI processing is done in the background.

“900,000 files processed in 80 minutes … fantastic results!”

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  • Deployable on individual workstations with or without GPUs, no need for any LAN, internet connectivity or server – no need for IT, extra hardware or complex setups!
  • No hidden or ongoing costs, no need for third-party licences, no need for extra training – a simple built-in solution.
  • Designed, developed and tested with law enforcement across the world, to best match the trends and content found in various regions, and thus maximise accuracy.



This breakthrough in technology is now available thanks to Semantics 21’s world-leading AI R&D team led by Professor Claude Chibelushi, who commented:

“The S21 R&D team have worked tirelessly to push the boundaries of what’s considered the ‘state-of-the-art’, to create a new benchmark for CSAM AI.

Although we intended to release S21 AC in early 2021, we decided to divert resources from other projects to get S21 AC into the hands of investigators even faster, especially with the ongoing COVID situation.

Its integration into LASERi-X, the fastest, most affordable and most functional product for categorisation and victim identification, is a game- changer and testament to why Semantics 21 is the most innovative company in the field”.


To request a copy of the S21 Auto-Categoriser please contact [email protected]


“S21 AC is dramatically improving the speed of my investigations, with the results being fantastically accurate, this is truly a game changer

Ashley Crowther, Digital Forensics Specialist, UK

“This feature quickly identifies the majority of CSAM images in your case and allows the Investigator to streamline the categorization process. Not only are the CSAM quickly identified, but so are other images that are not relevant to the investigation, which the investigation can quickly dismiss”
Constable Anthony Fasullo, Digital Forensics Unit, Chatham-Kent Police, Canada

“S21’s continuing commitment to support law enforcement tackle CSAM is unrivalled, and this AI will have a massive impact on our work
Federal Digital Forensics Unit Manager, USA



  • Not another ‘run-of-the-mill’ or ‘after-thought’ CSAM AI

Developed from the ground up, S21 AC uses proprietary algorithms and technologies specifically developed for CSAM AI, and tested against a diverse test set which was verified accurately by experts; enabling us to deliver unmatched accuracy and blazing speeds. Able to harness the power of GPUs, S21 AC has been shown to process 900,000 images in only 80 minutes (this is an actual result from one of our Certified Partners using their existing equipment). 

  • Unique bespoke artificial intelligence

Using bespoke AI, image and video media processed by the S21 AC are quickly analysed and the content predicted as containing CSAM, indicative CSAM, adult pornography, or non-notable media. Its unique decision-making process enables users to even filter S21 AC results based on how confident it is! 

  • Immediate cost effectiveness

S21 AC is free for all S21 LASERi-X users, simple to run and able to run from a local workstation (no server, network or internet needed – sorry IT!) meaning ZERO licence fee or training or setup costs! This means that users are ‘quids-up’ from the first second to the many hours saved by deploying S21 AC.

  • Reliable, practical, accurate – a step change

S21 AC has been engineered with the challenges of digital forensics in-mind, by the most innovative company in the field. To run it in-app, it is as simple as setting a checkbox; with investigators able to see results within seconds as the processing is done in realtime, while they can continue to use LASERi-X as normal. Deployment to over 30 organisations across the world has shown consistently high accuracy, quick performance and positive user engagement. 

  • A plugin or extension? 

S21 AC is natively built into S21 LASERi-X, as opposed to being a third-party plugin. S21 AC was developed alongside LASERi-X, to ensure maximum performance, usability and functionality, while minimising complexity.



When will S21 AC be available?

S21 AC is available immediately for all existing LASERi-X customers. New customers will be able to get S21 AC with S21 LASERi-X v2.1 which will be available in December. Please, get in contact for more details!

How much will it cost?

Free! You know how we work and our ethics. We believe something like this should be made accessible to all users as a free upgrade, we 100% want to support investigators and the important work that they do to find and rescue more victims. We do this all the time, implementing new features and requests (e.g. Flickerbook mode, facial analysis, GPU support, new AI … etc) without charging the user! It is another mark of our unwavering support and continued contribution towards the amazing work that you do to help keep us and our families safe. Thank you!

Surely no one ever gives anything good away for free?

Why not? Remember the saying “The best things in life are free”? S21 AC has been proven to provide high accuracy and processing performance when used by many organisations working on live case work. Semantics 21 has chosen to gift this capability back to the S21 community for their ongoing support and amazing work that they do in a difficult environment and are hampered by an even more difficult current climate. 


An industry leader at producing innovative technology, Semantics 21 embeds cutting-edge technology into solutions which address the need for advanced software in digital forensics investigations of images and videos. Constantly at the forefront in research and development, Semantics 21 delivers state-of-the-art solutions which empower investigators to: 

Find trusted evidence, faster;

for fairer and timely justice,

throughout the world.

The high capability of the company, to develop novel technology and make innovative products has been recognised through multiple prestigious awards.


Visit, email [email protected] , follow us on Twitter @semantics21 or call us, for more information and to organise a trial and training. UK phone: (01785) 330758, Canada phone: (647) 696 501, USA phone: (916) 619 1504

FREE LASERi-X, LASERi-t trial licences and COMPLIMENTARY training are available on demand.

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