We need to get to potential terrorists before radicalisation, not afterwards | Richard Barrett

Once an individual has fallen for extremist propaganda, it’s hard to change their mind. Better to spot the early signs• Richard Barrett is a former director of global counter-terrorism at MI6The attack in Streatham on Sunday carried out by Sudesh Amman – recently released from prison after serving time for terrorist-related offences – raises again the question of how to make prison more effective in dealing with this sort of offender. Inevitably there have been renewed cal