Here are the key findings of a report by the Intelligence and Security Committee into what prior knowledge intelligence and security services had of Lee Rigby's killers ahead of his murder.
- Lee Rigby's killers Michael Adebowale and Michael Adebolajo appeared in seven different agency investigations as low-level subjects of interest before they murdered the soldier.
- There were errors in agency operations, where processes were not followed, decisions not recorded or delays encountered
- The report concluded that despite the errors MI5, MI6 and GCHQ could not have prevented the murder of Fusilier Rigby
- Agencies had no knowledge of an online exchange between Adebowale and an overseas extremist in 2012 in which he reveals he intended to murder a soldier as it was not reported by a US web firm
- Report says the unnamed web firm 'however unintentionally' provided a 'safe haven' for terrorists
- 'Highly unlikely' agencies could have discovered the exchange before the attack
- 'Significant possibility' MI5 could have prevented the murder of Lee Rigby if the exchange had been reported
Lee Rigby's stepdad and sister criticised social media companies for failing to notify the authorities of users plotting a terror attack.
ITV's UK Editor Rohit Kachroo looks at the findings of a report into the extent of intelligence agencies' knowledge of Lee Rigby's killers