Cockett's Last Cock-up

Chief Inspector Nigel Cockett could have retired at the age of 55, but like a fool he stayed on for that last promotion that would raise his pension just a little more. Unfortunately, just then a corpse turned up in the holding cell of his own police station.
Inspector Manson, his young colleague fresh from police college—the chappy that was supposed to succeed him—seemed to think that he, Nigel, was the culprit. Just because he was the only person who had the key to the lock-up in his possession. “This won’t do at all,” the policeman thought, “I’ve been framed!”
So he called his old acquaintance Daisy Hayes on the phone. She was the only real-life sleuth he’d ever met with any talent for solving murders. He begged her to help him prove his innocence: “The only thing I can say for sure is that I didn’t do it!”
“This is your classical locked-room mystery, with a twist of lemon, and the chief suspect is none other than Nigel Cockett, of ‘D for Daisy’ fame. Our favourite blind sleuth could not resist the challenge! Serve ice-cold.” — The Weekly Banner
This 61k novel is a stand-alone in the Blind Sleuth series
The Blind Sleuth Mysteries Daisy Hayes was born in London in 1922. Her father was a bank manager, hoping for a son, but he had to settle for a blind daughter.
Now what do you do when your child is blind since birth and you have the means to do all that is necessary to help her? You hire a private tutor to stimulate her verbal development in the first years of her life, because you realize how vital language will become for her. Then you send her to an exclusive school where everything is done to develop the minds and resourcefulness of blind girls. There they teach them all these fancy techniques of spatial orientation and mind mapping. And before you know it, your darling daughter has developed an exceptional intellect that just seems to draw murder mysteries like a magnet…