He killed himself.

(I think it's off topic to discuss this, but I didn't like your misinformation.)

https://www.bristolpost.co.uk/news/bristol-news/kevin-crehan...

Thank you brave throwaway account for spreading lies, but while Crehan did pass away in December 2016 while serving his sentence, he was not murdered by "radical Muslims", nor was he killed by anyone. A police investigation and an independent coroner's inquest found no suspicious circumstances or foul play. The inquest concluded that he died alone in his cell from a drug overdose involving methadone.

Also, he was not sent to a "high-security prison full of radical Muslims", he was serving his time at HMP Bristol, which is a standard Category B local adult prison that houses mainstream inmates from the surrounding local courts.