Bernard Knight 
According to the Evidence [EPUB ebook] 

A forensic mystery of the 1950s — After starting their risky venture of a private forensic consultancy, Doctor Richard Pryor – now a Home Office pathologist – and forensic biologist Angela Bray have now become firmly established. An apparent bizarre suicide in a remote Welsh farm starts them on a new investigation, which is followed by an unusual request from the War Office. And when a Cotswold veterinary surgeon is charged with poisoning his ailing wife, can Pryor’s expert evidence save him from the gallows?