In possibly the least surprising development following the terrorist attack on Westminster:
'Prime Minister Theresa May has confirmed the Westminster attacker who killed three on Wednesday was "British-born" and had been investigated by security forces in the past.
Speaking in parliament, Mrs May said the man was known to police and MI5 and had been investigated "some years ago" "in relations to concerns about violent extremism".
However, she described him as a "peripheral figure" and said, "the case is historic"."
He was not part of the current intelligence picture", the Prime Minister added. "His identity is known to the police and MI5, and when operational consideration allow he will be publicly identified".'
This sums up the extent of the problem we face. He was investigated years ago and was deemed to be a peripheral figure and not part of the current intelligence picture. Some years later this peripheral figure carries out a terrorist attack at the heart of London.
How many more peripheral figures are there?
How many of them are ready and willing to kill?
Is it time for internment?