 Hannam was born in Paddington, London in 1908, the son of printer Walter Hannam from Worcester and Elizabeth Jane from Enniskillen, County Fermanagh.Hannam became famous in connection with the notorious Teddington Towpath Murders in 1953.During the trial, defence counsel Peter Rawlinson cross-examined Hannam at length, opening large holes in his evidence on how the confession said to have been made by the accused was obtained.