In 1892 FitzPatrick became the head of intelligence in the Johannesburg offices of Hermann Eckstein and Company (part of Wernher-Beit and Company). FitzPatrick became the secretary of the Reform Committee in Johannesburg in 1895. The Committee conspired to overthrow Paul Kruger's South African Republic government from 1895 to 1896. FitzPatrick also acted as go-between the Committee and Cecil Rhodes and Leander Starr Jameson in Cape Town. On 29 December 1895, Jameson led a failed raid from the Bechuanaland Protectorate (modern-day Botswana) to aid the conspirators in Johannesburg, but was stopped at Doornkop on 2 January 1896. FitzPatrick was charged with the others for high treason. Although sentenced to two years' imprisonment and a £2,000 fine, he was released in May 1896.