Andy Dufresne came to Shawshank looking to the other inmates like he was above them, his quiet, contemplative state misread as arrogance. Over the years, while becoming a master criminal at the heart of the Warden's money laundering scheme, he became a cornerstone of the prison's community before his escape. And when he emerged from his arduous journey through a river of unspeakable foulness, the audience cheered, because his innocence seemed so compelling that there could be no question of it. At least if you took his word for it, which the audience was forced to.
One compelling theory suggests that the whole Shawshank Redemption plot was in fact the complex machinations of an ice-cold killer, covering his tracks and working hard to convince even his friends of his innocence. The evidence, pointing to the parallel between Andy's love of chess and the intricate requirements of his plan to escape as well as the key point of the film's charming but unreliable narrator, is difficult to shake off once you've taken it in. And if it is true, it would seem that Andy's greatest trick was convincing the world, through the manipulation of poor Tommy, that someone else killed his wife, despite his proven genius in creating imaginary people.
In actual fact, Andy was coolly maneuvering his pieces for an attack on the Queen (Norton), who he simultaneously turns into a pantomime villain thanks to relaying his stories to Red, who never actually witnesses any of their interactions. And therein lies the genius of the supposed con job: Red is always removed from the real events and can never be considered a reliable narrator. He's spinning a tale weaved by Andy, who was capable of an immaculate swindle on Norton and the entire Shawshank system that Andy himself helped concoct to protect his escape.
While the theory completely changes the trajectory of the Shawshank Redemption plot, it isn't without merit, because it fits with what Andy manages to pull off. He had already invented someone as part of that fraud scheme for the Warden and over the decades had proved himself to be surprisingly elusive, able to hide huge secrets and also able to manipulate those around him to protect himself.
While the idea of him using Tommy to protect himself by planting the idea of suppression of the truth and ultimately of escape makes Andy far more villain than anti-hero, it's not hard to imagine the idea of a protégé groomed for months by a more impressive, intelligent elder. He proved in passing a secret message to Red about his escape that he knew how suggestion worked.
And if Andy was a killer, he would be more than willing to have someone die in the name of ensuring his own story of innocence was strengthened further (since he can be the only one who told Red about the confession Tommy heard).
