Read digital forensic expert Dr Matthew Sorell’s full report on David Speirs white powder video

The video and photographs that David Speirs claims are deepfakes are “authentic” with no indication of tampering, says a respected forensic expert. Read his full eight-page report.

Most of us, when looking at photographs and videos, see treasured moments with loved ones or adored pets, or memories made on nights out or trips away.

But through the keen, analytical eyes of Dr Matthew Sorell, those same photographs and videos appear very different.

“I’m not looking at what you’re looking at,” he said on Tuesday.

“I’m looking at shadows, I’m looking at reflections, I’m looking at the consistency of lighting and the consistency of how the image has been assembled.

“Do the colours make sense? Do the textures make sense?”

Dr Sorell is one of the world’s most renowned digital forensics expert – based in SA but in demand globally.

One of the still photos, left, and a screenshot of the video, right, captured on June 30.

He assesses the provenance and authenticity of digital data, particularly that from mobile phones, and the need for his work only grows with every new technological leap.

Dr Sorell assessed the David Speirs video and two photos – which the Member for Black claims are “deepfakes” – for The Advertiser.

His expert report concluded the files “appear to be authentic, internally consistent and without indications of tampering of content, metadata or file structure”.

READ THE FULL REPORT BELOW

On Tuesday, Dr Sorell said most people considered a “deepfake” to be any video or image that has been altered by artificial intelligence.

However, the term truly refers to materials in which a person’s face or voice has been altered or replaced, “maybe with some lip-synching”.

“We don’t really use deepfake for things like actions … it’s more difficult than most people can do, it’s quite involved to do that process,” he said.

“We are not talking about the complete fakery of an entire body.”

On Tuesday, he said a visual assessment of an image or video was only the beginning of the process.

Some files will still have their metadata – identifying details that point to the time and location of their creation – which can be checked.

Even if the metadata is available, however, Dr Sorell said “I still don’t trust that”.

A still image of the video timestamped 4.12am on June 30.

He demonstrated how easily metadata can be changed with a keystroke – but also showed how that change is not automatically reflected in the rest of the file structure.

That difference, he said, can be a key sign of tampering.

“If they weren’t consistent with one another, that would flag a potentially modified piece of data or photograph,” he said.

“I’m going to look deeper … I work down at the binary level, I’m actually looking into the file itself and seeing how that’s structured together.” To do that, Dr Sorell studies the file not as an image, but as its component hexadecimals – a 16-digitnumeral system translation of the data.

To the untrained eye, a screen filled with hexadecimals is reminiscent of the opening moments of the Matrix movies, with lines of code spiralling down.

“Because I grew up with computers in the 1970s, I learned to read this before I was even a teenager,” Dr Sorell said.

“If you’re going to Photoshop a photograph or deepfake a video, it’s not enough to just be able to change the content.

“You’ve actually got to be able to keep the (digital) container how it is, and that’s so hard I’ve actually not seen it done competently yet.”

In his report about the images of Mr Speirs, Dr Sorell wrote the image resolution and metadata of the photos appear “mutually consistent” with their content, even when reviewed at the hexadecimal level. I have checked multiple points of reference including the digital file structures of each supplied photograph and video, the embedded metadata and the content of each photograph/video,” he wrote.

“It is my opinion that each file is internally consistent and shows no indication of alteration of content or metadata. “I have also considered the characteristics of photograph alteration and video synthesis, so-called ‘deepfake’ video.

“I am unable to identify any of the characteristics of photograph manipulation such as shadow or reflection anomalies, temporal facial feature detail variations or hand movement anomalies.”

WHO IS DR MATTHEW SORELL

Dr Sorell is a world-renowned expert in digital forensic science, who has worked on some high profile cases in the past.

Over the past two decades, Dr Sorell has provided his expertise in more than 200 criminal matters as a consultant to police, prosecutors and defence counsel.

His evidence was crucial in last week’s decision, by the UK High Court, to block a husband from claiming his late wife’s $8.6m estate – because he had killed her.

Dr Matthew Sorell is principal consultant of Digital Forensic Sciences. Picture: Brenton Edwards

Though Donald McPherson was not criminally prosecuted over Paula Leeson’s 2017 drowning death, the court made a civil ruling that, on the balance of probabilities, he had taken her life.

Based in South Australia, Dr Sorell’s expert opinion played a key role in the case.

His specific experience and expertise is in mobile network operations – everything from telecommunication records to the records, multimedia files and data created by phones.

Dr Sorell teaches internationally and was a scientific adviser in Europe’s three-year FORMOBILE project, concerning mobile phone forensics at crime scenes and in court.

He is also a member of the INTERPOL Digital Forensic Experts Group.

Since 2017, he has been involved with active development of CCTV and mobile phone tracking tools in multiple criminal investigations.

He is the principal consultant of Digital Forensic Sciences Australia and Adjunct Professor of Digital Forensic Science at the Tallinn University of Technology in Estonia.

Dr Sorell is the Honorary Consul of the Republic of Estonia in SA.

He has held the position since October 2021.

Originally published as Read digital forensic expert Dr Matthew Sorell’s full report on David Speirs white powder video