She knows the letters' contents will add to the public perception of her as a callous and evil killer, but the discovery of photographs depicting the injuries Brady inflicted on her made her decide to go public.
In a detailed letter and interviews with `The Independent', she said she thought no one would believe her claims that Brady beat her and threatened to kill her mother, grandmother and sister if she did not participate. However, she now feels it is worth risking the wrath of Brady and the fallout from the release of the coded letters in order to make public her claims and the photographic evidence.
She admits the letters will not show her in a good light. She claims she wrote them according to subjects Brady had requested in advance.
"Over the seven months we were on remand, Brady compiled a notebook in which he wrote dozens of messages that I was to respond to in a code he'd devised," she said. "If the date on which either of us wrote a letter to each other was underlined, it meant there was a message in the letter." The code began six lines into the letter with the seventh and eighth words beginning the message; a line was missed - ie with no message words - and the seventh and eighth words continued the message.
"It carried on in this way, every other line, the seventh and eighth words, until the message was over. It was written in such a way as to make complete sense as a normal letter to whoever read it - the censor etc - whilst containing [secret] messages."
Hindley sent the following letter to Brady from Risley remand centre while awaiting trial. The words in italic are the ones Brady will have found using the code, starting from the sixth line:
"I've been thinking for a while, why don't you ask if you can go [end of line] to church on Sundays so we can at least see each other there? [End of line] It's your right to go there. You get some one to help with this. [End of line] See the Governor if necessary. There are places in the chapel for people [end of line] in your situation Ian, so ask someone to look into it for you. There's [end of line] someone here who goes with two officers. She's in here for killing her own [end of line] child and also for attempting to throw acid in her boyfriend's face. No-one [end of line] likes her; she's on Rule 43 of course. Re; your mention of facial expressions in your last letter, I, too, wish [end of line] I could have seen the one on Brett. His face was a picture when you stared him out!"
Asked why she wrote such a message, she said she did it only because Brady had asked for "stimulation" and had given her a list of subjects to write about. "He was so meticulous in the way he planned everything," she said. "He had a list of subjects from A to Z that I was to write about. It was like he was when he was planning the murders. Everything was always written down - even the number of buttons on his coat so he knew how many he should have when he got back."
Hindley says Brady passed details of the code before remand hearings at magistrates court while they were being held at Risley. Hindley says they were given 15 minutes to speak privately together. When she broke off contact with Brady, Hindley says she destroyed all his letters. However, he kept hers and has lodged them with his solicitor, Benedict Birnberg.
"When the abuse and duress and very probably those photographs are used at my appeal, Brady will be enraged," said Hindley. "And no doubt [he] will instruct Birnberg to reveal that and all the other messages from my letters to him."
Mr Birnberg confirmed that Brady had Hindley's letters but he could not recall his client ever mentioning a code.