Who was medical officer who signed death certificates for Rory O'Connor and l Liam Mellows executed in Mountjoy gaol Dublin 1922?

The medical officer who signed the death certificates for Rory O'Connor and Liam Mellows, both executed in Mountjoy Gaol in 1922, was Dr. John O'Connor. He was responsible for certifying their deaths following their execution by firing squad during the Irish Civil War.