A man who attacked two prison officers at Norwich Prison has been detained in hospital indefinitely.
Cairo Adams, 23, attacked the officers with a hand-made bladed weapon as he was being escorted for recreation time during the incident in June 2017.
He repeatedly hit one of the officers in the neck and hand, leaving the victim with nerve and tissue damage.
Adams was detained under the Mental Health Act and will be monitored if he is released back into the community.
He was cleared of attempted murder at a trial earlier this year.
"This was a nasty and unprovoked attack on two people who were simply doing their job," Detective Constable Robin French from Norwich CID said.
"The indefinite hospital order means Adams, who suffers from paranoid schizophrenia and personality disorder, cannot be discharged from hospital until he is no longer considered a risk to the public.
"The restriction order imposed also means if Adams is ever released, there are safeguards in place to monitor him.”