The blurb on the back:

Circumstantial Innocence
Lawrence Todhunter had decided that before his death he was going to commit a murder - so he did.
It was a flawless performance, with a glamorous actress as victim, and he was really quite proud of his accomplishment. In fact, he was not upset until another man was arrested for the killing.
Immediately, Todhunter resolved to confess, but when he did, no one believed him. And suddenly he realized that though he had indeed committed the perfect crime, he was going to have to prove himself guilty of it ...

So if you knew you had a terminal disease, with only a couple of months to live - and would therefore be unlikely to have to face trial, let alone punishment - who would you choose to kill? Obviously the name of Rupert Murdoch leaps immediately to mind, with those of Tony Blair, the Pope and Robbie Williams not far behind, but you have to remember that this book's from the 1930s. So Mussolini and Hitler are in the frame. They both get mentioned (in that order, curiously enough), but are discarded as possibilities since they only exist as an expression of political currents: 'Hitlerism wouldn't collapse if Hitler were killed. In fact the Jews in Germany would probably find themselves worse off still.' (p.31) Instead our hero, Lawrence Todhunter, finds someone who's making the lives of some decent people miserable. And kills her.

His problems really start, however, when someone else gets charged with the murder. Which leaves him in the tricky position of having to prove that he really is a killer. It's a nice twist on the detective story. We know whodunnit, and we know how and why he dunnit, which only leaves the question of why is it so damn difficult to find the conclusive evidence?

This is a real thing of beauty. It was filmed in 1941 as Flight From Destiny, which I haven't seen, but which I can't believe is a patch on the book. Part of the joy of the novel is the sheer length of it - for such a simple set-up, it does go on a bit, and in so doing it explores every possible nook and cranny, every variation on the theme that can be wrung out of the situation, leaving no tail untwisted, no nose untweaked.

And it's full of great little, unexpected angles. The police are deliberately obstructive, resenting the implication that they got the wrong man, whilst the News Chronicle uses the case to make a few salient points about the Spanish Civil War (bit of a dated joke, that one, but you'll appreciate it if you're a fan of newspaper history). Even better, Todhunter's brief is a very well-connected QC named Sir Edward Prettiboy, whose wonderful name is matched only by an ability to work the Establishment, a talent at which he excels:

Mr Todhunter had indeed been astonished at the reliance which Sir Ernest Prettiboy placed on his 'strings', as Mr Todhunter termed them to himself. One would have said that Sir Ernest was a man of fairly definite purpose and direct action, but it seemed that according to the rules of the game no one must ever do anything himself. Somebody else always had to be approached, and the more circuitously, the better, to do it for one. These persons Sir Ernest would refer to as 'a string to pull'. Old This could pull a string with the king's proctor, old That was at school with the attorney general, old the Other knew a second cousin of the home secretary's wife and might be a useful string. Everything must be done on personal grounds, never on the rights or wrongs of the actual case. Sir Ernest knew all these important persons himself, and apparently quite well; but he seemed to think that the home secretary's decision was much more likely to be influenced by an elderly aunt of the permanent secretary's, over a tea table in Bayswater, than by a discussion on the justice of hanging an innocent man in the cold formality of the home secretary's own office. It amazed Mr Todhunter still more that the solicitors, and indeed everyone who might be expected to know the ropes, not merely shared this view but seemed to think that no other view was possible.
Mr Chitterwick, with whom Mr Todhunter discussed this phenomenon, knew better and tried to explain the inert mass of unimaginative bureaucratic dead weight against which any reform or even any measure of plain humanity had to strive. (pp.194-195)

How can you resist a writing style that dry? It's up there with Hilaire Belloc's satirical novels. Oh, and if you have a scintilla of doubt left in your mind, check that dedication.