Funny enough, was a fella from Northampton way that done one of those. & another 'dodgy' character made it into a Ralph Fiennes book, fiction no doubt, but a few lads on here knew him & im sure have the odd tale.
Theirs that many back stories to the RR murders, it'll maybe never be unravelled. The people looking after the grass who's on the witness protection were up on conspiracy to supply charges and suspended for years (allegedly)! Ive never read a book about it, but theirs been maybe half a dozen films that I know of at least.