[1] The high number of attacks by the Provisional IRA in Great Britain had exercised British police forces.
Operation Comb had been instigated, involving approximately a thousand plain-clothes detectives deployed to observe London's streets.
On 6 December 1975, officers working for the Metropolitan Police chased Butler, Joe O'Connell, Hugh Doherty and Harry Duggan by car through London's streets after they'd witnessed the group directing automatic fire into Scott's restaurant in Mayfair.
With constant media coverage and after food parcels from the balcony above, appeals and days of negotiations, the four surrendered, staggering their exit between the release of their hostages.
[2] Butler and the three others were convicted of the murders of Roger Goad, Gordon Hamilton Fairley, Robert Anthony Lloyd, Graham Ronald Tuck, Audrey Edgson and John Francis Bately – all killed by bombs – and Ross McWhirter – shot at his home.