On 4 December 1909, Bigham was appointed the
Chief Constable of the Metropolitan Police
Criminal Investigation Department (CID). On 29 January 1914, he succeeded
Frederick Bullock as Assistant Commissioner "L", in charge of the Legal Department of
Scotland Yard. During the
First World War, he spent most of his time dealing with the control of
aliens, and in 1919 he was appointed
Companion of the Order of the Bath (CB). On 6 November 1922, Bigham and his colleague, Assistant Commissioner
Frank Elliott, were sent a box of chocolate
éclairs poisoned with
arsenic. However, they were suspicious and did not eat them. Walter Tatam, who had a history of mental problems, was later found guilty of attempted murder. In 1928, he became Assistant Commissioner "C", in charge of CID. He was appointed
Knight Commander of the Order of the British Empire (KBE) in the Metropolitan Police Centenary Honours of 3 June 1929. Following the sudden death of Sir
Charles Royds on 5 January 1931, Bigham succeeded him as Assistant Commissioner "A", in charge of administration and uniformed operations and with the courtesy title of Deputy Commissioner. He also immediately became
Acting Commissioner, as
Lord Byng was absent on medical leave in
France. Shortly afterwards, following a reorganisation, he became solely Deputy Commissioner, being succeeded as Assistant Commissioner "A" by
Lieutenant-Colonel David Allan. Bigham retired in January 1935. ==Family==