The London Bridge murders by convicted terrorist Usman Khan have renewed attention on the monitoring of extremists.
Police and MI5 knew about Khan and had jailed him for his role in a 2010 plot to attack the London Stock Exchange.
But that doesn’t mean there was a way to guarantee public safety after his automatic release last year, under the fixed-term sentence given at the Court of Appeal in 2013 by a panel of Sir Brian Leveson and two other judges.
One reason is the number of suspects. As a freed terrorist, Khan was one of MI5’s active “subjects of interest”. But with about 3,000 others and 20,000 “lower-risk” individuals to worry about, there aren’t sufficient resources for intensive surveillance of each one, despite significant funding rises for MI5 and counter-terrorism police.
Instead, Khan was subjected to “trip wire” monitoring, designed to pick up problematic changes in behaviour, on the grounds that there was nothing beyond his history to suspect an intent to attack.
The highest scrutiny is devoted to dozens of others judged to pose a greater threat. Such choices are not always right but are inevitable in a democracy that wants to avoid police state levels of surveillance.
The same applies to legal restrictions that govern round-the-clock monitoring. Warrants for this must be approved by a judge and pass strict tests that require recent evidence of potential terrorist intent. This was absent in Khan’s case.
Nor do arguments about inadequate probation and rehabilitation appear relevant. Khan seems to have been complying with the terms of his release until he struck. It’s not clear whether he was concealing his extremism or was genuinely seeking a new life but then suddenly reverted.
The only fail-safe way to stop terrorists willing to mount such attacks is to have them in prison. When they’re on the streets, surveillance and intelligence often keep us safe — but that can’t be guaranteed as last week’s events proved once again.
