CCTV Analysis and Court Presentation Material

Train CCTVCCTV Analysis

Following an Affray at a railway station CCTV images from the station and an on board train system were used by the prosecution in the form of a DVD compilation. We were instructed by one of the defence teams to analyse the CCTV evidence and clarify images containing their client for presentation in court.

Having viewed the DVD compilation disclosed to the defence we identified that the original Digital CCTV images had been converted to the DVD format. This can introduce artefacts, reduce edge detail and sometimes even miss out recorded frames. (see more here and here) so we advised that a copy of the original material should be requested so that we could carry out our analysis on the best evidence.

We identified that the timestamp used by both systems was not synchronised which made relating what could be seen from each system difficult and possibly misleading and produced material to identify the difference.  We produced clarified video and a document containing all of the relevant video images as stills in pdf format with the position of their client highlighted.

“At one stage in the proceedings, it [the pdf document] was referred to as the ‘bible’.”


After the completion of the trial the instructing solicitor said;
“The stills were very useful in terms of the on board footage and both other defence counsel said that this allowed them to explore points which they would otherwise not have been able to. At one stage in the proceedings, it [the pdf document] was referred to as the ‘bible’. Thank you as ever for your sterling work – and turnaround. I know that I always find the way in which the material is sent very useful and easy to access / use in terms of presentation (despite my lack of computer know how). Thanks again for your hard work!”
G. Bell of The Purkiss Partnership

We can help you!

If you have a case involving Audio, Digital Image or Video Evidence then please either call or click the button

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Save time by using a Forensic Video Analyst

Save time by using a Forensic Video Analyst

Is it worthwhile spending time reviewing CCTV evidence that may, if misunderstood, lead you down the wrong path? [Tweet this]

Hopefully your answer to that was no.

In the case of CCTV evidence it may prove a waste of time and effort to assume that the material disclosed is all of the material, is unbiased and in an appropriate format. You may also be missing an opportunity to examine all of the material.

A couple of short examples to illustrate why you might want to get a Forensic Video Analyst to review the CCTV evidence before you expend a lot of effort and possibly come to the wrong conclusion…..

‘Gesture’ by murder victim

A legal professional reviewed video evidence and thought that they could see the victim gesture towards the accused after the alleged assault which lead to his death. I won’t go into the relevance of the gesture but they repeatedly viewed the images provided to them and eventually became convinced of what they thought the images showed.

They came to us to clarify the images and to explore how they could easily show this  ‘Gesture’ to the court.

Firstly the images that had been provided to them had been converted to the DVD video format so we requested a copy of the original digital CCTV. We then examined that and found that the recording only contained six images per second from the relevant camera. The individual was in the distance, it was night time although the street lamps were on and he was wearing a dark long sleeve top. Analysis of the CCTV images before and after the one image were the ‘Gesture’ was seen showed that there were dark areas in the background that made it appear that the person raised their arms in that single frame as they moved along the pavement and across the dark areas in the background.


The CCTV images did not provide any evidence to support the ‘Gesture’ but an awful lot of their time had been spent on it.

Friend reviews evidence of theft

Three years ago an employee was accused by their employers of theft, the company carried out their own investigation which included seizing the relevant images from the locations digital CCTV system. They then made a complaint to the police and provided them with their findings and the original CCTV exhibit, the person was arrested and subsequently charged. The prosecution served a disc containing the video evidence together with other papers supporting their case.

The accused appointed a solicitor and the case progressed, a friend of the accused agreed to assist them by analysing the material including the video evidence.

The friend set about examining the material in detail. The video material was on a DVD without a menu and the video played continuously, the video showed the accused at the location going about their daily routine moving from one camera view to another. But then he noticed that the sequence didn’t make sense, some time periods were missing, some images had a time stamp but some didn’t. He thought that there was something sinister going on. [Tweet this]

Through the solicitor a request was made to the court for the original CCTV. Having been told that the prosecution had already served everything they were eventually supplied with another DVD. This had a navigation menu and what appeared to be 12 separate clips of video. Again a lengthy examination of the discs contents were made and compared against the original disc.

It was discovered that some new material had been added but some images that existed on the fist disc were not on the second. The content of both discs appeared to the friend to have been edited to provide a skewed and biased record of events and that there was, he believed, a conspiracy between the employers and police to prove their case.

Many adjournments later and with a week to go to the next trial date we received a phone call from the friend. They asked if we could help to make sense of the material and provide a professional opinion on what had taken place.

Our expert CCTV analysis quickly identified that neither disc was a copy of the original material produced by the internal investigator although the police stated that they had not edited the content.

In reality both discs simply contained an edited version of the original recording converted to the DVD video format, albeit they were produced with a bias towards the prosecution’s case.


Any further attempt to analyse the content of the images should have been made against the original recording.

The accused, the friend and the legal professionals could have saved a lot of time/money by asking an expert to review the material at the outset. [Tweet this]



Unlock Digital CCTV

Is a lawyers time well spent trying to play a video?

We recently helped a firm of Personal Injury Solicitors who were unable to view a video no matter what they tried. They were acting for a cyclist involved in an accident and they had received some Digital CCTV evidence on a disc which they needed to view.

Nothing wrong with the file?

The video playback software installed on their computers was unable to play the file. They made inquiries with the police and were told that there was nothing wrong with the file and that they needed to download a common codec pack, but this made no difference. They contacted the location from which the CCTV was sourced and received more advice, but they were still unable to view the images. Having exhausted the obvious options, and before they took a hammer to it, they searched the web (Google) for someone to help them to unlock Digital CCTV material and called us.

Media Player error messages

The dreaded pop up

Unlocking CCTV Material

Having received the disc from them we viewed its content and found that the file extension of the only file on the disc was “.AVI”, a fairly common file container format. We then examined the  file and found that it was in fact encoded using a proprietary codec not freely available on the internet. We were then able to extract the video images and create a video that they could play in Windows Media Player without any additional downloads. With the Digital CCTV unlocked they can now view the images and continue their work on the case.

There are many reasons you may not be able to view the video files on a disc such as CODEC issues, no suitable proprietary player, damaged disc or corrupt file data.

So what can you do?

If you have problems viewing video material as part of your case we can assist you by unlocking it from its proprietary format allowing you to view it on your computer.

If you have material served in the DVD-Video format  (How would I know?) then you may also want to find out if you can get a copy of the original export from the Digital CCTV (Why?).

Rather than getting frustrated with the material and distracted from your work, why not let us help you with your Audio or Video evidence problems, we’re only a phone call away.

Has the CCTV video evidence been converted to DVD-VIDEO?


Video tape recording converted to DVD-Video

It appears to have become common practice to convert CCTV video evidence to the DVD-Video format.

Why should Solicitors and courts care?

Our CCTV Analysis has shown that there can be issues with the quality of the conversion of the original material to DVD-Video in respect of image quality and it not always being a faithful representation of all the originally  recorded images.

Apart from the quality and veracity of the content it is unlikely that the Compilation DVD will  contain all of the material seized and you may possess information that requires additional images to be viewed.

See my previous article on the problems with using the DVD-Video format for evidential material. Click here

What to look for.

Here are some indicators to help you tell if the CCTV evidence has been re-formatted to the DVD-Video format;

  • The disc may be identified with an easy to see DVD-R or DVD+R text or logo, not a definitive test but enough to suggest that the material needs further examination.

    DVD+R disc

    Look for disc markings

  • When you insert the DVD into your computer either a window opens with options to play the DVD using one of your installed software players or one of those players automatically opens.
    pop up window when disc inserted

    Pop up window


  • Once the software player is open you may see a menu which might provide some information about the content of the video and who created it. The menu will also contain text or small thumbnails which act as buttons that allow you to select which video to play. Some DVD-videos do not have a menu and the video images play straightaway. – See more at:

    DVD Menu Screens

    Selection of DVD menu screens

  • With the video playing there are likely to be visual clues such as;
    • There might be a wide border, typically black, around the video.
    • The images may show the video playing in another player that you are unable to control.
    • The camera view may change suddenly indicating that the video may have been created as a compilation of views to show the images that best support the editors point.
    • Some of the text around the image such as the date and time may be blurred, imagine what the conversion has done to the image detail.
  • Using your computer explore the contents of the disc in the same way you would folders on your hard drive, if you find a folder entitled VIDEO_TS and it contains files with the extensions .IFO, .BUP & .VOB you have a DVD-Video.

What to do next?

If you want to ensure that you have all of the recorded images at the best possible quality and the CCTV system uses a Digital Video Recorder (DVR) you should request a bit for bit copy of the original material or if the system is tape based you will require access to the original master video tape recording.

Or if you prefer you can send the material to us together with copies of relevant case papers and we will carry out an Initial Assessment and provide a report on its suitability for analysis or as a format for presenting the evidence.