For her role in the Moors Murders, Myra Hindley was for many years described as ‘‘the most hated woman in Britain’’. So when her escape plot from HMP Holloway in late 1973 is part-aided by then prison guard Patricia Cairns, there is dismay at why anyone would go to such lengths for someone convicted of Hindley’s crimes.

What was unearthed during the police investigation, however, was that Hindley and Cairns had established a relationship - not only through interactions within the prison, but through the deeper communication of letter writing that spanned some two years.

In this episode of Bad People, Dr Julia Shaw and Sofie Hagen explore how Hindley became an “unwitting architect” of whole-life sentences, and discuss the citizens who write to inmates. Why do people become prison pen pals and when is it unethical?

CREDITS Presenters: Dr Julia Shaw and Sofie Hagen Produced by Hannah Ward Editor: Anna Lacey Music: Matt Chandler Commissioning Executive: Dylan Haskins Commissioning Assistant Producer: Adam Eland #BadPeople_BBC Bad People is a BBC Audio Science Production for BBC Sounds.