James Johnson, 39, from Cheltenham has been jailed for 7 years after being found guilty of the manslaughter of 39-year-old Luke Derriman from Slough, at HMP Hewell in Redditch. Both men were inmates at the prison.
Johnson threw a single punch at Mr Derriman in his cell at HMP Hewell at approximately 3.05pm on 23 January 2018.
Derriman was discovered unconscious in his cell by prison staff and was taken to hospital where he later died from his injuries.
Johnson denied the charge but was found guilty of manslaughter by unanimous verdict yesterday following a trial at Worcester Crown Court.
Detective Inspector James Bayliss from West Mercia Police said: “Prison investigations are by their very nature challenging, and violence like this and in such an establishment will always be thoroughly investigated.
“Luke Derriman sustained a fatal blow and the verdict today shows the severity of the offence committed by James Johnson.
“His death serves to remind us that one punch can have devastating consequences and ultimately – as in this case – can kill.
“This result can in no way bring Luke back and so our thoughts remain with his family and friends.”