Therecare a lot of movies where plot takes place in a prison, with 'innocent' in-mates, cruel warden and a breathtaking escape but I'm almost sure that the director wanted to pay tribute to Bogart& Bacall's Dark Passage. There are some particular elements in the plot that resemble the 50 years old film such as; the ending scene on a south American Pacific beach (here Mexico then it was Peru), a bus ride thru the Mexican border, an innocent fugitive etc. (Morgan Feeeman of course is not Bacall...ha ha ).The rest of the story, or better to say almost all of it is an entirely different . Tim Robins and M.F work together with harmony , even pouring some humor into the gloomy atmosphere of the Shawshank prison.
Review of The Shawshank Redemption
