Three men already in custody appeared in court in Napanee today to face charges in relation to an attempted murder at Millhaven Institution.
A joint forces investigation between the OPP, Kingston Police and Correctional Services Canada began on August 3 following an incident at the prison.
Don Johnson, 24, is facing charges of attempted murder, carrying a concealed weapon and possession of a weapon for a dangerous purpose.
Jerry Lewis, 21, and Manpreet Singh, 25, are facing being party to the offence of attempted murder charges.
The investigation is ongoing.