In May 1920 up to a hundred armed men broke into Kilmorna House and held Vicars at gunpoint while they attempted to break into the house's strongroom. On 14 April 1921, he was taken from Kilmorna House, which was set alight, and shot dead in front of his wife. According to the communiqué issued from Dublin Castle, thirty armed men took him from his bed and shot him, leaving a placard around his neck denouncing him as an informer. On 27 April, as an official reprisal, four shops were destroyed by Crown Forces in the town of Listowel. The proclamation given under Martial law and ordering their demolition also stated: