I was delighted to spot Guilty?, a black and white crime film dating back to 1956, in the Talking Pictures schedule. This movie, also known as By Whose Hand?, is based on Michael Gilbert's novel Death Has Deep Roots, published five years earlier, which I've read and enjoyed a couple of times. As far as I know, it's the only film based on a Gilbert book other than the better-known Danger Within, based on Death in Captivity. This is rather surprising, given that Gilbert wrote vividly; his work was very suitable for screen adaptation.
Gilbert didn't write the screenplay - that was done by someone called Maurice J. Wilson. The credits reveal that additional dialogue was supplied by Ernest Dudley - who along with Gilbert was one of the founders of the Crime Writers' Association. But there is an even more intriguing connection to be deduced from the credits. The soundtrack was composed by Bruce Montgomery - the real name of Gilbert's fellow Detection Club member Edmund Crispin. Quite something to have a fellow crime writer produce the music for a film of your book!
The story combines a courtroom drama - a young Frenchwoman is on trial for her life- with an adventurous investigation into a criminal conspiracy that dates back to the war and the Nazi occupation of France (hence the "deep roots"). The accused's solicitor is Nap Rumbold, one of those appealing characters who crop up sporadically in Gilbert's work without quite becoming major series characters.
John Justin plays Rumbold, and does a a good job with a meaty part. Andree Debarr is his glamorous client, and Barbara Laage is a mysterious blonde woman who seems to be following Rumbold around for no particular reason. A sound cast includes such reliable actors as Russell Napier and Sydney Tafler., while Donald Wolfit plays the judge. I enjoyed the film, even though it doesn't match the excellence of the novel.