Khairi Saadallah, the Libyan refugee who has been detained on suspicion of perpetrating the knife attack in Reading, was released early from prison, was enrolled in the government’s Prevent deradicalisation scheme, and is believed to have been known to the UK’s security services as a possible terror suspect before the attack. Saadallah had been sentenced in October 2019 to 25 months and 20 days in prison for breaching a suspended jail term, racially motivated assault, criminal damage, and affray (public fighting) — yet only served 17 months and 20 days behind bars. In March, the Court of Appeal decided to...