The family of London Bridge attacker Usman Khan have said they are "saddened and shocked" by what happened and "totally condemn his actions".

Khan, who was convicted of a terrorism offence in 2012, killed Jack Merritt, 25, and Saskia Jones, 23, at a prisoner rehabilitation event on Friday.

The BBC's legal correspondent Clive Coleman looks at why Khan was released from prison on licence in December 2018.