Officers get smart to catch criminals via their phones

Published on Friday 17 September 2010 17:13

Reports of the recent arrest of the three Pakistani test cricketers in connection with allegations of "spot bet fixing" mentioned that their mobile phones had been seized. And that's what will happen to the phone of anyone picked up in Scotland tonight found in possession of some illegal substance.

Just as new illnesses beget new and expensive treatments that send shivers down the spine of NHS bookkeepers, so the tidal wave of new mobile and smartphones is making unprecedented demands on the investigative capacity of Britain's police forces. A new industry has emerged to examine material recovered from mobile phones to assist police and defence lawyers in criminal matters .

But it is also generating business from companies who fear improper conduct by an employee - everything from industrial espionage to harassment of colleagues. The fundamental premise of forensic science is that "every contact leaves a trace" paraphrased from the "exchange principle" developed by the 20th-century pioneer of the discipline, Dr Edmond Locard.

Phones are no different. Every call, picture and text message potentially leaves a trace. The problem is that with an industry estimate of 50 million or so mobile devices currently in circulation in the UK it is likely that anyone detained by police in connection with a crime will have a mobile phone in his pocket or her handbag. Or sometimes in less appealing places. Which of them will be worth the time and expense of interrogation in pursuit of evidence?

Detective Sergeant Dave Black at Tayside Police says his unit was set up as recently as 2003, initially to carry out forensic examination of computers, but phones began to arrive too. "We handled 80 phones in that first year. Last year the number was 1,600. Ironically, the new phones are effectively handheld computers with the number of functions built into them and their memory capacity is bigger than some of the big desktop computers only seven years ago."

While most Scottish forces now have a phone interrogation capacity, the recently unified Scottish Police Services Authority has its own eight-strong unit dealing with handsets and computers recovered in connection with serious and organised crime.

Detective Inspector Keith McDevitt says, "It's probably more accurate to describe them as digital media communication devices and that will include games consoles through to smartphones. As consumers we mainly pay attention to the functions that we access, but they are supported by a logical digital structure.There is a good chance that a memory of the activity on that device will still be stored and the task for us is to find a way of accessing it."

Phones are involved or associated with three broad types of offence. First are those in which the use of the phone itself is the crime. The most common, and apparently still the most flouted, is using a phone while driving. The lucky perpetrators get away with a fixed penalty and points on their licence.

Secondly are crimes in which the device is used to commit an offence, such as bullying between children, harassment, stalking or, as a team photo of footballers has found, transmission of sexual images that secured both headlines in the tabloid newspapers and a place on the sex offender register.

The third and most resource-intensive category is the evidence stored in the phone memory connecting its owner with serious crime, from drug dealing to armed robbery and murder. As with DNA evidence, the data within the phone may often be helpful in eliminating the suspect from the investigation but the headlines and the sense of achievement for the investigators follow the recovery of evidence that proves crucial to pinning the crime to the perpetrator.

DS Black says: "We don't recover everything every time. But we secured a conviction of a serious drug dealer in Dundee largely on the basis of the evidence recovered from his phone. In the end we never found any drugs in his possession, but there were so many incoming and outgoing text messages on his phone referring to his customers that tied into the comings and goings at his home, the jury was convinced. He got five years."

Ignorance of the technology played a part in the downfall of several high-profile offenders, including Ian Huntley, who murdered Jessica Chapman and Holly Wells in Soham in 2002; and Imran Shahid and Zeeshan Shahid and Mohammed Faisal Mushtaq, convicted of the murder of Glasgow teenager, Kriss Donald in 2004. In both cases evidence that located their phones to particular mobile phone masts helped undermine their story about their whereabouts at the time of the crime. "Cell site" analysis cannot provide a precise location to street level but can indicate a locality.

Some of the information that is retrievable seems unbelievably basic. The predictive text function on even basic handsets can be a useful source of regularly used names and places. All phones have an address book and a list of recently dialled numbers.

Even cheap phones now have a camera that will time and date an image that can usually be recovered even if the user thinks he has deleted it. More modern handsets will now geo-tag the image so its location, as well as time and date, can be determined.

Even when criminals make the effort to delete incriminating call records or texts, in many cases they can be recovered. The data may still exist on the sim card memory as "available space" when the owner thinks it has gone.With even bigger 16GB memory, far beyond the capacity of most of us to fill, the newer generation of phones are less likely to need to overwrite data stored and so provide more places for an analyst to look.

Evidence recovered from mobile phones has rarely been challenged in court on its scientific robustness. As the requirement for forensic telecommunications analysis has expanded, a private industry has grown around it. The industry is largely unregulated and so individual "experts" have been challenged on their credibility.

Most defence challenges focus on whether the handset was lawfully seized by police in the first place and therefore whether any data recovered is admissible as evidence.

DS Black of Tayside says he has been called to give evidence in person on only half a dozen occasions. "There are procedures we have to follow to ensure anything we recover is robust," he says. "The first thing the officer is instructed to do is switch off the phone so it cannot interact with its network after it has been seized. When we get it to our workshop we will make a clone of the sim card but disable its ability to communicate with the network. The data will be retrieved from the clone so there is no risk of overwriting or interfering with the data on the original."

The joint report, in which his findings are corroborated by another officer, is invariably accepted by the defence.

Some evidence in the Kriss Donald trial, and more recently in the prosecution of Peter Chapman for the 2009 murder of the girl he groomed on the internet, Ashleigh Hall, was given by analysts employed by Forensic Telecommunications Ltd, the biggest player in Britain. Managing Director Shaun Hipgrave says: "Investigation is always a step behind the advances the manufacturers are developing. They're not trying to hide anything, just develop applications that will sell to their consumers.

"We support police investigators throughout the UK but I can see a problem for them on the horizon of new Home Office forensic regulations coming into force in January 2013. It cost us 250,000 to meet those standards now and I wonder, in a time of spending cuts, how many forces will want to make that sort of investment."