One of the Metropolitan Police's most senior officers has said that the Investigatory Powers Bill (IP Bill), also known as the Snoopers' Charter, is necessary to help "find people innocent".
"It's not just about finding and convicting people, but proving people innocent," Metropolitan Police deputy assistant commissioner Neil Basu said at a briefing to discuss the Bill.
Basu gave the slightly confusing example of a murder case in which "all the circumstantial evidence" pointed to a particular man's guilt, "but I felt he was hiding something".
It turned out that the suspect was trying to keep police from discovering his illicit relationship with a 15-year-old, which the police eventually uncovered by gaining access to his computing and mobile devices.
The evidence absolved him from being charged with murder based on circumstantial evidence, as Basu admitted, and instead earned him convictions for sex offences and a place on the sex offenders' register.
The police said that accessing more of this type of data, especially people's internet connection records from ISPs and mobile operators, is now necessary because increasingly this is where key information for cases lies.
"The reason why we need communications data hasn't changed in decades. It's the way we get data that has changed. We still need to know who criminals are contacting, how they are doing it, where they are when they do it, what devices they are using, and whether they are accessing 'criminal sites'," said Basu.
"Our requirements haven't changed. The technology environment in which criminals work has changed fundamentally. We do need the law updated in order to respond to that digital challenge."
Basu emphasised that bureaucratic processes that the police have to follow to acquire and exploit electronic data are onerous. "And quite rightly too because they are the safeguards," he added. "I think the IP Bill will put even more safeguards on it."
He went on to say that the new powers would be used to combat the usual array of crooks that the police always cite - terrorists, organised criminals, paedophiles, murderers and rapists - but added that he saw the police's job as "protecting the vulnerable", meaning that the powers were also required for investigations into allegations of harassment, online bullying and "grooming".
"It can't all be just be about serious crime, depending on what your definition is. We use these powers to save the most vulnerable people in society. So we use it for high-risk missing persons. It's a huge part of our work particularly if they're very young, very old, very ill or mentally disturbed or suicidal," he said.
"And then there's 'lesser crime', if I can use that rather unfortunate expression. There'll be crime that doesn't meet any kind of serious crime threshold. Grooming and harassment are two really good examples where they are effectively pre-cursor offences. Criminologists will tell you that can potentially lead to much more serious offending."
However, Basu was keen to assert that the powers are not as far-reaching and intrusive as many people have suggested.
The comments come after MPs voted through the IP Bill by a huge majority, although with some of the more contentious elements dialled down. It now passes to the House of Lords for further debate.
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