Serving as an intelligence officer for the Dublin Brigade of the Irish Republican Army, and as a Dáil Court judge he was imprisoned by the British in 1921.
[3] On 20 December 1922 he was shot dead in his shop at 5 Rathmines Road, Dublin,[4] by anti-Treaty IRA Volunteer Robert Bonfield.
The young man reached into the pocket of his overcoat a drew a revolver, he fired twice at O'Dwyer at point-blank range.
Two republicans, Frank Lawlor and the actual assassin, Robert Bonfield, were later killed by Free State forces in revenge for the shooting of Dwyer.
[1] He was a member of the Peace Committee of ten men which sat in May 1922 which brought about the agreement between Michael Collins and Éamon de Valera.