‘Witness for the Prosecution’ is a lovely film, as well as an enjoyable book. I watched the 2016 film version recently, set out in two parts on Acorn TV. I purchased the book shortly thereafter.
There were also film adaptations of the book in 1957 and 1982. I watched the earlier one when I was a youngster. I expect at least one of these three films should be available at your local library. And if not there, you can purchase or rent them through Amazon. The book is also widely available at libraries and book stores.
Read – Witness for the Prosecution