Ordeal By Innocence by Agatha Christie in Paperback

 

The evidence that exonerates a young man convicted of his adopted mother's murder arrives too late to save him from a life behind bars. Who is the real culprit? Dr. Arthur Calgary takes a ferry across the Rubicon River to Sunny Point, the Argyle family's residence. A year ago, the family matriarch was killed and Jack, one of her sons, was found guilty and sentenced to life in prison. But Jack maintained his innocence throughout the trial, insisting that he was hitchhiking on the night of the murder and was picked up by a mysterious man in a dark car. The police dismissed his story, unable to find any evidence of this individual. However, Calgary turns out to be the stranger, but he arrives too late to save Jack who unfortunately passes away from pneumonia after only serving six months of his sentence.