And now, most surprisingly of all, perhaps, given her Conservative upbringing in East Anglia, she has surfaced as a Labour candidate in the election for the Welsh Assembly.
She is standing in Delyn, North-east Wales and according to the Institute of Welsh Politics at the University of Wales, Aberystwyth, she has a good chance of winning the seat. "I'm not sure whether I voted or how I voted during my early years in the police. I imagine if I did vote it would have been Conservative. My parents voted Conservative," Ms Halford said.
She joined the police in 1962 and in her 21 years in London went from constable to chief superintendent, before becoming an assistant chief constable on Merseyside. Her conversion to Labour began in London. "I've always had a social conscience. I was very unhappy about people being forced to live in cardboard boxes."
Her two-year fight to prove she had been the victim of discrimination on Merseyside - she was rejected for promotion nine times - ended with an out-of-court settlement with both sides claiming victory.
Ms Halford moved to north Wales in 1994, when she joined the Labour Party and was soonasked to become a councillor. Inevitably, she was also seconded to the Police Authority. Equally inevitably, perhaps, she has been involved in running battles with Michael Argent, the chief constable.
Some of her political rivals - she is running against three women - claim she is obsessed with police misdemeanours. She accuses senior police of undermining complaints procedures to protect officers from investigation. If it is an obsession, it is shared by other members of the Police Authority and by two businessmen who have set up the "Campaign for Justice", seeking a Home Office inquiry into police activities in north Wales.
Ms Halford is anxious to show she is not a one-issue politician. She believes the Welsh Assembly will be far closer to the people it represents. She likes its "transparency and inclusiveness" and the balance between the genders. "I want the Assembly to behave ethically, not to squander money."
However, the phrase "equal opportunities" is never far from her lips. Would she advise a young woman to become a police officer? "There are dinosaurs and chauvinists in every walk of life. But I generally think that most senior police officers are trying harder. The police service is a wonderfully fulfilling career or, should I say, way of life."Reuse content