Fred Dinenage looks back over the life of John Straffen; at the age of 21 he strangled two little girls but escaped the hangman's noose due to his low IQ of just 58. After six months at Broadmoor Straffen escaped and committed a third murder on another young girl in a local village. This time he was reprimanded in maximum security prisons and remained so for the next 55 years. Straffen died in prison in 2007 but continues to carry the title of Britain's longest serving prisoner.

• Fred Dinenage