The inmate had already served 15 years on death row for “robbery with violence” before his sentence was commuted to life imprisonment.
Mr Karuri was listening to a radio broadcast of the Kenyan president’s annual pardons while mopping block D in the state prison.
Upon realising his name wouldn’t be called he castrated himself using a razor blade and continued to mop up the floors until he collapsed from loss of blood.
He was discovered an hour later when inmates returned to see pools of blood leading to one of the cells.
A prison warder who spoke to Karuri said because he didn’t receive a pardon “he decided to chop off his manhood because it was useless to him since he cannot have children now,".
50 prisoners won Uhuru’s clemency on Jamhuri Day, the day Kenya marked 50 years of Uhuru (national independence in Africa).
Inmates say Karuri had been suffering with depression for several months and had been transferred to a section of the prison which houses inmates who suffer from mental health