US
Usman Khan killed two people and wounded three while on conditional release from prison in November 29 knife attack
Man already convicted of a terrorist offence stabbed two people to death and wounded three others on London Bridge
Video footage of the confrontation showed Khan being challenged by a man, wielding a tusk
Usman Khan, who had been convicted of terrorism offences was released from prison last year
The bomb went off on Friday's morning in a crowded carriage
Witnesses say mosque imam ‘protected suspect from angry worshippers’
US president has been invited to make a coveted state visit to UK but no dates have been set
Authorities have said Butt was known to police and the domestic security service MI5
Two Australians were among seven people killed in Saturday's attack
May has previously been criticised for scrapping house arrest rules known as 'control orders'