Ecoutez l'histoire de....

Serge Gainsbourg and Brigitte Bardot perform 'Bonnie and Clyde', based on the poem by Bonnie Parker.
As was discussed in the lecture, it seems many, if not all of the characters who eventually end up as folk heroes transform from murderous self-serving criminals into popular peoples' champions. This seems to stem from the social conditions which prevail at the time. In Bonnie and Clyde's case, they happened to rob banks at a time of great economic hardship. If you add to that the romanticism of their relationship, you have the ingredients of what makes a legend.
The Krays are an interesting example, whilst they were obviously phsycotic murderers, their reputation of 'only killing their own' and being nice to their mom lingers. Perhaps they were seen as harking back to the tradition of honour amongst thieves, in a world that was changing faster than many of that generation would have liked. Before the end of the 60s there would be the public outrage at the 'Moors murders', which I imagine would have increased the rose tinted view of the east-end pair.
Stuart Lee observes a similar phenomenon in his thoughts on the IRA vs the 9/11 and 7/11 bombers: