Fake Sheikh's digital downfall

WHEN police and enforcement agencies want help with complex cases, there’s frequently one man they turn to.

That man is Angus Marshall, boss of Darlington-based digital forensics company n-gate, although few of us will have heard of him.

Major drugs crime, murder investigations, counter-terrorism and fraud, it’s all in day’s work for Mr Marshall, although the nature of what he does means he is reluctant to talk about ongoing or sensitive cases.

The 49-year-old, an independent digital evidence examiner who has helped to write international standards in the field, is registered with the National Crime Agency as a specialist advisor who can be called for help with digital evidence of all types, e-mails, instant messaging, that kind of thing, which is so key now for many of us, criminals included, in the way we communicate.

MESSAGING: Much of Angus Marshall's work now centres on mobile phone messaging apps

With just weeks to go before the start of Sun journalist Mahmood’s trial at London’s Old Bailey, Marshall, a former academic at Teesside University, was asked to examine evidence against the defendant - known as the king of the tabloid undercover sting - and his driver, Alan Smith, who was also found guilty of plotting to pervert the course of justice.

Both men were said to have tampered with evidence in the collapsed drugs trial of singer and former X-Factor judge Tulisa Contostavlos, changing a statement and deleting incriminating e-mails.

“I tend to get called in late in the day as things are getting close to court because people don’t have the time or the expertise to deal with things quickly,” says Mr Marshall.

“The key thing in the Fake Sheikh trial is that they seemed to have done their best to destroy the evidence, but in doing so gaps were created that we were able to use to build up a hypothesis of what was going on. I was able to show that some e-mails had been sent from (Alan Smith’s account) to police, but there were no copies of them.

“The other thing was looking at timings in term of access to the account and helping the police to tie that up with the some of the phone records. There did seem to be a pattern of activity that very shortly after the e-mails were accessed there were phone calls being made backwards and forwards so it looked like there was some sort of collusion.”

Mr Marshall, who has also collaborated with ‘Wire in the Blood’ crime author Val McDermid, rejects suggestions that his role is to “beef up” cases which may have flaws.

“I am an independent expert witness, my duty to the court is to tell the truth, not to try and strengthen anyone’s case,” he says.

“Most of the work happens outside of the court room, I spend quite a lot of time discussing things with the defence expert trying to reach agreement on the common areas where there is no dispute and also presenting the disputed areas in a way that can be sensibly dealt with by the court.

"In this particular case neither of us needed to appear and the material was just read out for the benefit of the judge and jury.”

Increasingly Mr Marshall’s work involves developing techniques for analysing data produced by mobile phone apps like WhatsApp and SnapChat.

“Drug dealers are now wise to the fact that mobile phones can be tracked and calls traced, so a lot of the time people are using secure messaging instead,” he says.

“The problem for the police is the technology company does not store messages in plain text, they use encryption, and the only place they can be read is either on the sending handset or the receiving handset. Even if the police eventually get a copy it is in a format that is not particularly useable to them.”

Mr Marshall describes an ongoing battle between investigators and tech companies, who want to protect their users’ privacy, making it harder to retrieve data, and admits that the former are constantly playing catch up.

He works alone – that way it is easier to show that correct processes have been followed – but has a few people he occasionally calls on for assistance.

“What I do needs to be private a lot of the time, but I crave intellectual debate with other people in the field. I am though a visiting fellow at the Open University and I’m allied to a team there that is active in cyber security and digital forensics.”

Mr Marshall says while most of his work is with law enforcement agencies, it can be replicated in the corporate environment with many businesses increasingly worried about issues such as hacking and employee theft of confidential data.

“A lot of smaller businesses for some reason believe that there is no-one out there willing and able to help them with cyber security so they don’t go looking for that level of assistance. I can tell them what’s going wrong and the improvements they can make to protect themselves and their bottom line.”

For more information about n-gate, including guides for businesses, visit the website www.n-gate.net